Xin Zhang

Bimetallic thin film NiCo–NiCoO2@NC as a superior bifunctional electrocatalyst for overall water splitting in alkaline media

Co-reporter:Yun Xiao;Pengfang Zhang;Xiaoping Dai;Yangde Ma;Yao Wang;Yan Jiang;Mengzhao Liu;Yue Wang

Journal of Materials Chemistry A 2017 vol. 5(Issue 30) pp:15901-15912

Publication Date(Web):2017/08/01

DOI:10.1039/C7TA03629A

Non-precious bifunctional electrocatalysts with high water splitting activity are of paramount importance in reducing energy losses in alkaline environments. Herein, we report NiCo–NiCoO2 heterostructures embedded in N-doped carbon (NiCo–NiCoO2@NC) as an efficient bifunctional catalyst for overall water splitting in alkaline media. Partially reduced nickel and cobalt interfaced with nickel cobalt oxide result from thermal decomposition of nickel cobalt double hydroxide precursors encapsulated in high surface area carbon. Bimetallic thin film NiCo–NiCoO2@NC exhibits a synergy of two active metals – Ni and Co, achieving remarkably small onset potentials of 0 and 200 mV, and overpotentials of 94 and 318 mV at 10 mA cm−2 for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, and achieving TOFs at η = 500 mV more than 2-fold of Pt/C in the HER and IrO2 in the OER. Momentously, a water electrolyzer that achieves 20 mA cm−2 at a voltage of 1.44 V is fabricated by utilizing cheap non-precious NiCo–NiCoO2@NC as anode and cathode catalysts simultaneously. Thanks to the protective carbon coating and the mutual aid of Ni–Co alloy and NiCoO2, NiCo–NiCoO2@NC maintains 20 mA cm−2 for at least 50 h in alkaline media without trivial activity losses. The prominent synergetic and structural effects have been extensively discussed to shed light on the overall water splitting electrocatalyst design.

Microwave-assisted synthesis of ultrafine Au nanoparticles immobilized on MOF-199 in high loading as efficient catalysts for a three-component coupling reaction

Co-reporter:Yan Jiang;Xiaoping Dai;Wen Zhang;Qiang Sheng;Hongying Zhuo

Nano Research 2017 Volume 10( Issue 3) pp:876-889

Publication Date(Web):2017 March

DOI:10.1007/s12274-016-1341-1

Controlled integration of ultrafine metal nanoparticles (MNPs) and metal–organic frameworks (MOFs) has drawn much attention due to their unique physical and chemical properties. However, the development of a one-step strategy for preparing ultrafine MNPs within MOFs still remains a great challenge. Herein, a facile synthetic approach toward the abovementioned composites was developed. In contrast to the conventional approach, these hybrids were prepared by the direct mixing of metal and MOF precursors in the reaction solution assisted by microwave irradiation. Impressively, the Au/MOF-199 composite with uniformly distributed ultrafine Au nanoparticles could be fabricated in only two minutes, and the Au loading could be increased up to a level of 5.13%. The multifunctional Au/MOF-199 catalysts exhibited high turnover numbers (TONs) and turnover frequencies (TOFs) in the three-component coupling reaction of formaldehyde, phenylacetylene, and piperidine (A3-coupling). Owing to the confinement effect of MOF-199, the 5.13%Au/MOF-199 catalyst could be recycled for five runs without serious loss of activity, with no obvious aggregation of Au NPs detected.

Microwave-assisted synthesis of multiply-twinned Au–Ag nanocrystals on reduced graphene oxide for high catalytic performance towards hydrogen evolution reaction

Co-reporter:Yuchen Qin, Xiaoping Dai, Xin Zhang, Xingliang Huang, Hui Sun, Daowei Gao, Yanbing Yu, Pengfang Zhang, Yan Jiang, Hongying Zhuo, Axiang Jin and Hai Wang

Journal of Materials Chemistry A 2016 vol. 4(Issue 10) pp:3865-3871

Publication Date(Web):10 Feb 2016

DOI:10.1039/C5TA10428A

Nanocrystals (NCs) with a multiply-twinned structure possess great potential in the field of electrocatalysis. Reduced graphene oxide (rGO) has been employed as a support to further improve the stability and activity of catalysts. However, the twinned structure is thermodynamically unstable due to the high total free energy, and it is difficult to control the shape of the crystals during preparation, especially when grown directly on the surface of rGO. Herein, multiply-twinned structural Au–Ag decahedra and icosahedra were grown directly in situ on rGO through a facile approach under microwave irradiation. Thanks to the synergy of abundant twin defects and the electronic effect of the intimate contact/interaction between the Au–Ag alloy and the rGO, these as-prepared Au–Ag NCs/rGO hybrids exhibit excellent activity and stability towards the hydrogen evolution reaction. In particular, Au–Ag icosahedra/rGO exhibits Pt-like electrocatalytic activity and enhanced stability compared to commercial Pt/C.

Metallic Cobalt Encapsulated in Bamboo-Like and Nitrogen-Rich Carbonitride Nanotubes for Hydrogen Evolution Reaction

Co-reporter:Xiaoping Dai, Zhanzhao Li, Yangde Ma, Mengzhao Liu, Kangli Du, Haixia Su, Hongying Zhuo, Lei Yu, Hui Sun, and Xin Zhang

ACS Applied Materials & Interfaces 2016 Volume 8(Issue 10) pp:6439

Publication Date(Web):February 26, 2016

DOI:10.1021/acsami.5b11717

Despite being technically possible, the hydrogen production by means of electrocatalytic water splitting is still practically unreachable mainly because of the lack of inexpensive and high active catalysts. Herein, a novel and facile approach by melamine polymerization, exfoliation and Co2+-assisted thermal annealing is developed to fabricate Co nanoparticles embedded in bamboo-like and nitrogen-rich carbonitride nanotubes (Co@NCN). The electronic interaction between the embedded Co nanoparticles and N-rich carbonitride nanotubes could strongly promote the HER performance. The optimized Co@NCN-800 exhibits outstanding HER activity with an onset potential of −89 mV (vs RHE), a large exchange current density of 62.2 μA cm–2, and small Tafel slope of 82 mV dec–1, as well as excellent stability (5000 cycles) in acid media, demonstrating the potential for the replacement of Pt-based catalysts. Control experiments reveal that the superior performance should be ascribed to the synergistic effects between embedded Co nanoparticles and N-rich carbonitride nanotubes, which originate from the high pyridinic N content, fast charge transfer rate from Co particles to electrodes via electronic coupling, and porous and bamboo-like carbonitride nanotubes for more active sites in HER.Keywords: carbonitride nanotubes; cobalt embedment; hydrogen evolution reaction; nitrogen-rich doping; synergistic effects

Fe/IRMOF-3 derived porous carbons as non-precious metal electrocatalysts with high activity and stability towards oxygen reduction reaction

Co-reporter:Hui Sun, Haixia Su, Xingyu Ma, Pengfang Zhang, Xin Zhang, Xiaoping Dai, Jinsen Gao, Chi Chen, Shi-Gang Sun

Electrochimica Acta 2016 Volume 205() pp:53-61

Publication Date(Web):1 July 2016

DOI:10.1016/j.electacta.2016.04.037

By doping iron into isoreticular metal organic framework-3 (IRMOF-3) as a precursor and then annealing at 900 °C under inert gas atmosphere, we have successfully prepared high efficient electrocatalyst of x%Fe/IRMOF-3-900 (x ranges from 1% to 10%) with porous carbon sphere structure. The electrocatalytic properties of the x%Fe/IRMOF-3-900 towards oxygen reduction reaction (ORR) are investigated by using rotating ring disk electrode (RRDE). The results demonstrate that the 1%Fe/IRMOF-3-900 exhibits the highest ORR activity: the onset and half-wave potentials are measured at 1.02 V and 0.88 V vs. RHE, respectively, together with electron transfer number of 3.90 at 0.4 V, kinetic current density of 4.5 mA cm−2 at 0.88 V, and excellent longtime stability in alkaline solution. Such high ORR activity is is superior to many MOFs derived noble metal free electrocatalysts reported so far, and attributed to that the 1%Fe doped could retain the well-defined cubic morphology of the IRMOF-3, resulting in high surface area and large total pore volume, high nitrogen content and high density of electrocatalytic active N-species. This study provides a new strategy for preparation of non-precious metal ORR catalysts using the MOF as a precursor.A novel 1%Fe/IRMOF-3-900 catalyst was prepared by doping Fe into IRMOF-3 and annealing at 900 °C under N2 flow, which showed the excellent ORR activity and excellent longtime stability.

Fabrication of ultrafine manganese oxide-decorated carbon nanofibers for high-performance electrochemical capacitors

Co-reporter:Ying Yang, Sungsik Lee, Dennis E. Brown, Hairui Zhao, Xinsong Li, Daqiang Jiang, Shijie Hao, Yongxiang Zhao, Daoyong Cong, Xin Zhang, Yang Ren

Electrochimica Acta 2016 Volume 211() pp:524-532

Publication Date(Web):1 September 2016

DOI:10.1016/j.electacta.2016.06.012

•Facile synthesis of MnOn-CNF composites by construction and evolution of Mn-ZnBTC fibers.•Excellent accessibility, high porosity, tight contact and superior conductivity are integrated.•Remarkable capacitance of up to 18290 F g−1 per active mass of the manganese(IV) oxide.•Superior stability of cycling up to 5000 times with a high capacitance retention ratio of 98%.Ultrafine manganese oxide-decorated carbon nanofibers (MnOn-CNF, 1.3 < n < 2.0) as a new type of electrode materials are facilely fabricated by direct conversion of Mn, Zn-trimesic acid (H3BTC) metal organic framework fibers (Mn-ZnBTC). The construction and evolution of Mn-ZnBTC fibers are investigated by SEM and in situ high-energy XRD. The manganese oxides are highly dispersed onto the porous carbon nanofibers formed simultaneously, verified by TEM, X-ray absorption fine structure (XAFS), Raman, ICP-AES and N2 adsorption techniques. As expected, the resulting MnOn-CNF composites are highly stable, and can be cycled up to 5000 times with a high capacitance retention ratio of 98% in electrochemical capacitor measurements. They show a high capacitance of up to 179 F g−1 per mass of the composite electrode, and a remarkable capacitance of up to 18290 F g−1 per active mass of the manganese(IV) oxide, significantly exceeding the theoretical specific capacitance of manganese(IV) oxide (1370 F g−1). The maximum energy density is up to 19.7 Wh kg−1 at the current density of 0.25 A g−1, even orders higher than those of reported electric double-layer capacitors and pseudocapacitors. The excellent capacitive performance can be ascribed to the joint effect of easy accessibility, high porosity, tight contact and superior conductivity integrated in final MnOn-CNF composites.Morphology controlled synthesis of Mn, Zn-containing metal organic framework fibers was carried out by varying the assembly time. Such a fiber precursor was converted to a new type of ultrafine manganese oxide-decorated carbon nanofiber upon pyrolyzed. This synthesis integrates excellent accessibility, high porosity, tight contact and superior conductivity in the final products, and thus exhibits a remarkable capacitance of up to 18290 F g−1 per active mass of the manganese(IV) oxide, high stability of cycling up to 5000 times, as well as the maximum energy density is up to 19.7 Wh kg−1 at the current density of 0.25 A g−1.

Reduced Graphene Oxide/O-MWCNT Hybrids Functionalized with p-Phenylenediamine as High-Performance MoS2 Electrocatalyst Support for Hydrogen Evolution Reaction

Co-reporter:Zhanzhao Li

The Journal of Physical Chemistry C 2016 Volume 120(Issue 3) pp:1478-1487

Publication Date(Web):January 5, 2016

DOI:10.1021/acs.jpcc.5b09523

Efficient hydrogen evolution through water splitting at low overpotentials is crucial to develop renewable energy technology, which depends on the design of efficient and durable electrocatalysts composed of earth-abundant elements. Herein, a highly and stable electrocatalyst for hydrogen evolution reaction (HER) has been developed on the basis of MoS2 on p-phenylenediamine (PPD)-functionalized reduced graphene oxide/O-containing carbon nanotubes (rGO/O-MWCNT) hybrids via facile and green hydrothermal process. Among the prepared catalysts, the optimized MoS2/rGO/PPD/O-MWCNT with nanosized and highly dispersed MoS2 sheets provides a large amount of available edge sites and the improved electron transfer in 3D conductive networks. It exhibits excellent HER activity with a low overpotential of 90 mV and large current density of 47.6 mA·cm–2 at 200 mV, as well as excellent stability in an acidic medium. The Tafel slope of 48 mV·dec–1 reveals the Volmer–Heyrovsky mechanism for HER. Thus, this work paves a potential pathway for designing efficient MoS2-based electrocatalysts for HER by functionalized conductive substrates.

Supported single Au(III) ion catalysts for high performance in the reactions of 1,3-dicarbonyls with alcohols

Co-reporter:Daowei Gao;Ying Yang;Xiaoping Dai;Hui Sun;Yuchen Qin

Nano Research 2016 Volume 9( Issue 4) pp:985-995

Publication Date(Web):2016 April

DOI:10.1007/s12274-016-0986-0

The high cost and poor atom utilization efficiency of noble metal catalysts have limited their industrial applications. Herein, we designed CeO2-supported single Au(III) ion catalysts with ultra-low gold loading that can enhance the utilization efficiency of gold atoms and bridge the gap between homogeneous and heterogeneous gold catalysis. These catalysts were highly active and reusable for the reaction of 1,3-dicarbonyls with alcohols. The catalytic turnover number of CeO2-supported single Au(III) ion catalysts was much higher than that of the homogeneous catalyst NaAuCl4. In addition, the effects of gold loading and the drying method for the catalysts on the organic reactions were systematically explored. In-depth investigation of the structure–property relationship by highresolution transmission electron microscopy, hydrogen temperature-programmed reduction, X-ray absorption near edge structure analysis, UV–vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy revealed that the isolated Au(III) ions were related to the active sites for the synthesis of β-substituted cyclohexenone and that CeO2 was responsible for yielding ketonic ester.

Molybdenum Polysulfide Anchored on Porous Zr-Metal Organic Framework To Enhance the Performance of Hydrogen Evolution Reaction

Co-reporter:Xiaoping Dai

The Journal of Physical Chemistry C 2016 Volume 120(Issue 23) pp:12539-12548

Publication Date(Web):May 27, 2016

DOI:10.1021/acs.jpcc.6b02818

Replacement of precious platinum with efficient and low-cost catalysts for electrocatalytic hydrogen evolution reaction (HER) at low overpotentials holds tremendous promise for clean energy devices. Herein, molybdenum polysulfide (MoSx) anchored on a porous Zr-metal organic framework (Zr-MOF, UiO-66-NH2) by chemical interactions is fabricated by a facile and one-pot solvothermal method for HER application. The distinctive design of the Zr-MOF stabilized MoSx composite enables remarkable electrochemical HER activity with a Tafel slope of 59 mV·dec–1, a lower onset potential of nearly 125 mV, and a cathode current of 10 mA·cm–2 at an overpotential of 200 mV, which also exhibits excellent durability in an acid medium. The superior HER performance should ascribe to the fast electron transport from the less conducting MoSx nanosheets to the electrode, high effective surface area, and number of active sites, as well as the favorable delivery for local protons in the porous Zr-MOF structure during the electrocatalytic reaction. Thus, this work paves a potential pathway for designing efficient Mo-based HER electrocatalysts by the combination of molybdenum polysulfide and versatile proton-conductive MOFs.

Strongly Coupled FeNi Alloys/NiFe2O4@Carbonitride Layers-Assembled Microboxes for Enhanced Oxygen Evolution Reaction

Co-reporter:Yangde Ma, Xiaoping DaiMengzhao Liu, Jiaxi Yong, Hongyan Qiao, Axiang Jin, Zhanzhao Li, Xingliang Huang, Hai Wang, Xin Zhang

ACS Applied Materials & Interfaces 2016 Volume 8(Issue 50) pp:

Publication Date(Web):November 23, 2016

DOI:10.1021/acsami.6b11821

Hydrogen produced from electrocatalytic water splitting is a promising route due to the sustainable powers derived from the solar and wind energy. However, the sluggish kinetics at the anode for water splitting makes the highly effective and inexpensive electrocatalysts desirable in oxygen evolution reaction (OER) by structure and composition modulations. Metal–organic frameworks (MOFs) have been intensively used as the templates/precursors to synthesize complex hollow structures for various energy-related applications. Herein, an effective and facile template-engaged strategy originated from bimetal MOFs is developed to construct hollow microcubes assembled by interconnected nanopolyhedron, consisting of intimately dominant FeNi alloys coupled with a small NiFe2O4 oxide, which was confined within carbonitride outer shell (denoted as FeNi/NiFe2O4@NC) via one-step annealing treatment. The optimized FeNi/NiFe2O4@NC exhibits excellent electrocatalytic performances toward OER in alkaline media, showing 10 mA·cm–2 at η = 316 mV, lower Tafel slope (60 mV·dec–1), and excellent durability without decay after 5000 CV cycles, which also surpasses the IrO2 catalyst and most of non-noble catalysts in the OER, demonstrating a great perspective. The superior OER performance is ascribed to the hollow interior for fast mass transport, in situ formed strong coupling between FeNi alloys and NiFe2O4 for electron transfer, and the protection of carbonitride layers for long stability.Keywords: carbonitride layers; iron−nickel alloy; microboxes; NiFe2O4 oxide; oxygen evolution reaction;

One-Pot Synthesis of Ternary Pt–Ni–Cu Nanocrystals with High Catalytic Performance

Co-reporter:Pengfang Zhang, Xiaoping Dai, Xin Zhang, Zhikun Chen, Ying Yang, Hui Sun, Xiubing Wang, Hai Wang, Meiling Wang, Haixia Su, Di Li, Xinsong Li, and Yuchen Qin

Chemistry of Materials 2015 Volume 27(Issue 18) pp:6402

Publication Date(Web):August 31, 2015

DOI:10.1021/acs.chemmater.5b02575

Shape-controlled synthesis of multicomponent metal nanocrystals (NCs) bounded by high-index facets (HIFs) is of significant importance in the design and synthesis of highly active catalysts. It is a highly challenging task to design and synthesize ternary alloy NCs with HIFs due to the formidable difficulties in controlling the nucleation/growth kinetics of NCs in the presence of three metal precursors with different reduction potentials. We report herein, for the first time, the preparation of Pt–Ni–Cu alloy NCs by tuning their shape from crossed, dendritic, concave nanocubic (CNC) to rough octahedral (ROH) NCs through a facile one-pot solvothermal synthesis method. Specifically, the crossed and CNC Pt–Ni–Cu alloy NCs are bounded by high-index {hk0} facets and ROH with rich lattice defects. The electrocatalytic activities of these Pt–Ni–Cu alloy NCs toward methanol and formic acid oxidation were tested. It was shown that these Pt–Ni–Cu alloy NCs exhibited enhanced activity and stability compared to commercial Pt black and Pt/C catalysts as well as previous Pt–Ni and Pt CNCs under the same reaction conditions, demonstrating the superior electrocatalytic activity of Pt–Ni–Cu ternary alloys compared to monometal and binary Pt–Ni NCs. Surprisingly, we have found that the Pt–Ni–Cu ROH NCs have exhibited a higher specific catalytic activity than the crossed and CNC Pt–Ni–Cu alloy NCs with HIFs. The electronic and structure effects have been extensively discussed to shed light on the excellent electrocatalytic performance of Pt–Ni–Cu ROH NCs.

Platinum–cobalt nanocrystals synthesized under different atmospheres for high catalytic performance in methanol electro-oxidation

Co-reporter:Yuchen Qin, Xin Zhang, Xiaoping Dai, Hui Sun, Ying Yang, Qingxiao Shi, Daowei Gao and Hai Wang

Journal of Materials Chemistry A 2015 vol. 3(Issue 20) pp:10671-10676

Publication Date(Web):09 Apr 2015

DOI:10.1039/C5TA01950H

Pt–Co nanocrystals with cube, dendrite and sphere shapes have been fabricated in air, hydrogen and nitrogen, respectively, at ambient pressure or 1 MPa. The Pt–Co nanocrystals with a chain-like structure, synthesized in nitrogen at 1 MPa, exhibited superior electrocatalytic activity and stability towards the methanol oxidation reaction.

Mercaptosilane-assisted synthesis of sub-nanosized Pt particles within hierarchically porous ZSM-5/SBA-15 materials and their enhanced hydrogenation properties

Co-reporter:Daowei Gao, Anmin Zheng, Xin Zhang, Hui Sun, Xiaoping Dai, Ying Yang, Hai Wang, Yuchen Qin, Shutao Xu and Aijun Duan

Nanoscale 2015 vol. 7(Issue 25) pp:10918-10924

Publication Date(Web):20 May 2015

DOI:10.1039/C5NR02749G

A novel catalyst that consists of sub-nanosized Pt particles within hierarchically porous ZSM-5/SBA-15 materials was synthesized. This catalyst exhibited high stability and a hierarchically porous structure of a micro–mesoporous composite and possessed a high density of active sites by confinement of sub-nanosized Pt particles within small-pore zeolites, showing high catalytic properties for the hydrogenation of 1,3-butadiene and cyclooctadiene at room temperature.

Self-assembly of monodispersed hierarchically porous Beta-SBA-15 with different morphologies and its hydro-upgrading performances for FCC gasoline

Co-reporter:Daowei Gao, Aijun Duan, Xin Zhang, Kebin Chi, Zhen Zhao, Jianmei Li, Yuchen Qin, Xilong Wang and Chunming Xu

Journal of Materials Chemistry A 2015 vol. 3(Issue 32) pp:16501-16512

Publication Date(Web):08 Jul 2015

DOI:10.1039/C5TA03671B

Micro-mesoporous Beta-SBA-15 materials with platelet, sphere, short-rod and long-rod morphologies were in situ synthesized and used as the catalyst supports for hydro-upgrading of FCC gasoline. The characterization results revealed that the Beta-SBA-15 composites possessed both SBA-15 and Beta structures. And the materials with different morphologies exhibited different Brönsted and Lewis acid sites and pore sizes due to their corresponding synthesis conditions. The platelet Beta-SBA-15 which possessed short mesochannels with a large pore diameter had high diffusion ability. The sphere Beta-SBA-15 with more mesopore cavities, large surface area and suitable acidity exhibited outstanding isomerization and aromatization abilities. The catalytic results confirmed that the platelet CoMo/ABS-PL exhibited a high hydrodesulfurization (HDS) conversion (97.6%) while the sphere CoMo/ABS-SP catalyst showed the superior research octane number (RON) preservation ability, which were better than those of CoMo/ABS-SR (short-rod) and CoMo/ABS-LR (long-rod) catalysts. The excellent hydrodesulfurization, isomerization and aromatization abilities of CoMo/ABS-PL and CoMo/ABS-SP were attributed to the special morphology, mesochannels and appropriate acidity properties of the catalysts. Thus, the as-synthesized platelet and sphere Beta-SBA-15 materials have potential application in FCC gasoline hydro-upgrading.

Co-Doped MoS2 Nanosheets with the Dominant CoMoS Phase Coated on Carbon as an Excellent Electrocatalyst for Hydrogen Evolution

Co-reporter:Xiaoping Dai, Kangli Du, Zhanzhao Li, Mengzhao Liu, Yangde Ma, Hui Sun, Xin Zhang, and Ying Yang

ACS Applied Materials & Interfaces 2015 Volume 7(Issue 49) pp:27242

Publication Date(Web):November 24, 2015

DOI:10.1021/acsami.5b08420

Highly active and low-cost catalysts for hydrogen evolution reaction (HER) are crucial for the development of efficient water splitting. Molybdenum disulfide (MoS2) nanosheets possess unique physical and chemical properties, which make them promising candidates for HER. Herein, we reported a facile, effective, and scalable strategy by a deposition–precipitation method to fabricate metal-doped (Fe, Co, Ni) molybdenum sulfide with a few layers on carbon black as noble metal–free electrocatalysts for HER. The CoMoS phase after thermal annealing in Co-doped MoS2 plays a crucial role for the enhanced HER. The optimized Co-doped MoS2 catalyst shows superior HER performance with a high exchange current density of 0.03 mA·cm–2, low onset potential of 90 mV, and small Tafel slope of 50 mV·dec–1, which also exhibits excellent stability of 10000 cycles with negligible loss of the cathodic current. The superior HER activity originates from the synergistically structural and electronic modulations between MoS2 and Co ions, abundant defects in the active edge sites, as well as the good balance between active sites and electronic conductivity. Thanks to their ease of synthesis, low cost, and high activity, the Co-doped MoS2 catalysts appear to be promising HER catalysts for electrochemical water splitting.Keywords: Co-doping; CoMoS phase; deposition−precipitation method; hydrogen evolution reaction; MoS2

Enhanced hydrogen evolution reaction on few–layer MoS2 nanosheets–coated functionalized carbon nanotubes

Co-reporter:Xiaoping Dai, Kangli Du, Zhanzhao Li, Hui Sun, Ying Yang, Wen Zhang, Xin Zhang

International Journal of Hydrogen Energy 2015 Volume 40(Issue 29) pp:8877-8888

Publication Date(Web):3 August 2015

DOI:10.1016/j.ijhydene.2015.05.062

•MoS2 nanosheets–coated functionalized MWCNTs were successfully synthesized.•The MoS2/N–MWCNT exhibited an outstanding HER performance and excellent stability.•The superior performance are attributed to thin MoS2, N–doping and rich bridging S22−.The oxygen– or nitrogen–functionalized multiwalled carbon nanotubes (O– or N–MWCNT) coated with few–layer MoS2 nanosheets (MoS2/MWCNTs) were successfully synthesized by a facile hydrothermal method. The results suggest that the N–MWCNT is favorable for the dispersion of few–layer MoS2 nanosheets due to the strong interaction between the N-containing groups and Mo precursor. The N–MWCNT coated with few–layer MoS2 (MoS2/N–MWCNT) exhibits the highest HER activity: onset potential of 90 mV vs. reversible hydrogen electrode, Tafel slope of 40 mV dec−1, high current density of 80.3 mA cm−2 at overpotential 0.2 V, together with excellent stability during 10,000 cycles. Such high HER activity is superior to most of MoS2–based catalysts reported so far, and attributed to the intimate contacts between highly conductive network of N–MWCNT and thin MoS2 nanosheets, the high quantity of unsaturated sulfur atoms or the bridging S22−, and high pyridinic and graphitic N concentrations. This work shows that the few–layer MoS2 nanosheets coated on conductive N–doped MWCNT has a great potential for electrocatalytic hydrogen evolution.

Morphology Design of IRMOF-3 Crystal by Coordination Modulation

Co-reporter:Di Li, Hai Wang, Xin Zhang, Hui Sun, Xiaoping Dai, Ying Yang, Lei Ran, Xinsong Li, Xingyu Ma, and Daowei Gao

Crystal Growth & Design 2014 Volume 14(Issue 11) pp:5856-5864

Publication Date(Web):September 18, 2014

DOI:10.1021/cg501089f

A one-pot synthesis design on shape-controlled growth of Zn-based isoreticular metal–organic framework (i.e., IRMOF-3) was carried out in this work with the controllable crystal morphological evolution from simple cubes to several complex shapes. A new synthetic protocol was devised where poly(vinylpyrrolidone) (PVP), noble metal source (AgNO3), mixed solvents (N,N-dimethylformamide (DMF)–ethanol mixture) and tetramethylammonium bromide (TMAB) were mutually introduced to the reaction medium as surfactant, adjuvant, accelerator, and structure-directing agent (SDA), respectively. Meanwhile, the crystallization process was investigated by a series of time-dependent experiments. Indeed, the added modulators and crystallization time were able to regulate the growth and thus the morphology of the final products. The resulting homogeneous IRMOF-3-Ag-n materials with unique and novel crystal morphologies were characterized via scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermogravimetric and differential thermal analyses (TG-DTA), transmission electron microscopy (TEM), infrared spectrum (IR), and optical microscope characterizations. Various shapes of IRMOF-3-Ag-n crystals as sorbents for capturing dibenzothiophene (DBT) were evaluated. Among all the morphology-controlled samples, IRMOF-3-Ag-5 with hollow sphere morphology was demonstrated to show the highest DBT capture capacity due to its unique morphology.

Catalysis by metal–organic frameworks: proline and gold functionalized MOFs for the aldol and three-component coupling reactions

Co-reporter:Liu Lili, Zhang Xin, Rang Shumin, Yang Ying, Dai Xiaoping, Gao Jinsen, Xu Chunming and He Jing

RSC Advances 2014 vol. 4(Issue 25) pp:13093-13107

Publication Date(Web):26 Feb 2014

DOI:10.1039/C4RA01269K

Translation of homogeneous catalysis into heterogeneous catalysis is a promising solution to green and sustainable development in the chemical industry. Recent research has shown that metal–organic frameworks (MOFs) could bridge the gap between homogeneous and heterogeneous catalysis. We successfully prepared for the first time a novel homochiral Zn-containing MOF referred to as CUP-1 based on the mixed linkers of 2-aminoterephthalic acid and L-lactic acid in a one-pot synthesis. The free NH2 group in the homochiral framework of CUP-1, similar to the well known achiral IRMOF-3, is potentially available for undergoing a variety of organic transformations, as demonstrated by choosing the auxiliary chiral L-proline and nano gold to functionalize MOFs with postsynthetic modification and one-pot synthesis strategies. IRMOF-3, CUP-1 and their functionalized samples were in-depth characterized by X-ray diffraction, N2 adsorption–desorption, optical and transmission electron microscopy, infrared spectroscopy, solid state nuclear magnetic resonance, thermogravimetric and differential thermal analysis, and temperature-programmed reduction. L-Proline functionalized IRMOF-3 shows fair to excellent enantioselectivity (up to 98%) in asymmetrical aldol reactions of aldehydes and acetone with higher turnover numbers and catalytic stabilities than the homogeneous counterpart. The gold functionalized CUP-1 catalysts are found to be highly active, stable and reusable for the three-component coupling reactions of aldehydes, alkynes and amines. This work provides general methods to functionalize MOFs with the active ligand and metal nanoparticles for fabrication of highly efficient MOF-based heterogeneous catalysts.

Synthesis of PtNi Alloy Nanocrystals with High-Index Facets and Enhanced Electrocatalytic Properties

Co-reporter:Xiling Xu;Dr. Xin Zhang;Dr. Hui Sun;Dr. Ying Yang;Dr. Xiaoping Dai;Dr. Jinsen Gao;Xueyong Li;Pengfang Zhang;Hong-Hui Wang;Neng-Fei Yu;Dr. Shi-Gang Sun

Angewandte Chemie 2014 Volume 126( Issue 46) pp:12730-12735

Publication Date(Web):

DOI:10.1002/ange.201406497

Abstract

The shape-controlled synthesis of multicomponent metal nanocrystals (NCs) bounded by high-index facets (HIFs) is of significant importance in the design and synthesis of high-activity catalysts. We report herein the preparation of Pt–Ni alloy NCs by tuning their shape from concave-nanocubic (CNC) to nanocubic and hexoctahedral (HOH). Owing to the synergy of the HIFs and the electronic effect of the Pt–Ni alloy, the as-prepared CNC and HOH Pt–Ni alloy NCs exhibited excellent catalytic properties for the electrooxidation of methanol and formic acid, as well as for the oxygen reduction reaction (ORR).

Synthesis of PtNi Alloy Nanocrystals with High-Index Facets and Enhanced Electrocatalytic Properties

Co-reporter:Xiling Xu;Dr. Xin Zhang;Dr. Hui Sun;Dr. Ying Yang;Dr. Xiaoping Dai;Dr. Jinsen Gao;Xueyong Li;Pengfang Zhang;Hong-Hui Wang;Neng-Fei Yu;Dr. Shi-Gang Sun

Angewandte Chemie International Edition 2014 Volume 53( Issue 46) pp:12522-12527

Publication Date(Web):

DOI:10.1002/anie.201406497

Abstract

The shape-controlled synthesis of multicomponent metal nanocrystals (NCs) bounded by high-index facets (HIFs) is of significant importance in the design and synthesis of high-activity catalysts. We report herein the preparation of Pt–Ni alloy NCs by tuning their shape from concave-nanocubic (CNC) to nanocubic and hexoctahedral (HOH). Owing to the synergy of the HIFs and the electronic effect of the Pt–Ni alloy, the as-prepared CNC and HOH Pt–Ni alloy NCs exhibited excellent catalytic properties for the electrooxidation of methanol and formic acid, as well as for the oxygen reduction reaction (ORR).

Heterobimetallic MetalOrganic Framework as a Precursor to Prepare a Nickel/Nanoporous Carbon Composite Catalyst for 4-Nitrophenol Reduction

Co-reporter:Dr. Ying Yang;Dr. Ying Zhang;Dr. Cheng Jun Sun;Xinsong Li;Wen Zhang;Xiaohui Ma;Dr. Yang Ren;Dr. Xin Zhang

ChemCatChem 2014 Volume 6( Issue 11) pp:3084-3090

Publication Date(Web):

DOI:10.1002/cctc.201402607

Abstract

Nickel/nanoporous carbon (Ni/NPC) composites are facilely prepared by direct pyrolysis of nonporous heterobimetallic zinc–nickel–terephthalate frameworks (Zn_1−xNi_xMOF, x≈0–1, MOF=metal–organic framework) at 1223 K in situ. Tailoring the Ni/Zn ratio creates densely populated and small Ni nanocrystals (Ni NCs) while maintaining sufficient porosity and surface area in the final product, which exhibits the largest activity factor (9.2 s⁻¹ g⁻¹) and excellent stability toward 4-nitrophenol reduction.

Highly stable and active PtNiFe dandelion-like alloys for methanol electrooxidation

Co-reporter:Zhenguo Guo, Xiaoping Dai, Ying Yang, Zhicheng Zhang, Xin Zhang, Shiqi Mi, Kai Xu and Yongfeng Li

Journal of Materials Chemistry A 2013 vol. 1(Issue 42) pp:13252-13260

Publication Date(Web):16 Aug 2013

DOI:10.1039/C3TA12894F

Novel PtNiFe dandelion-like alloys are fabricated by a facile etching strategy. The ternary alloys and single-walled carbon nanotube (SWNT) immobilized PtNiFe alloys exhibit high activity and poison tolerance with remarkable stability for methanol oxidation reaction (MOR). The excellent electro-catalytic performance is ascribed to the unique dandelion-like nanostructure.

Assembling photoluminescent tri(8-quinolinolato)aluminum into periodic mesoporous organosilicas

Co-reporter:Ying Yang, Xin Zhang, Qiubin Kan

Journal of Colloid and Interface Science 2013 Volume 411() pp:138-144

Publication Date(Web):1 December 2013

DOI:10.1016/j.jcis.2013.08.036

Highlights•Alq3-containing PMOs were synthesized via a convenient one-pot method.•Alq3-containing PMOs combine the photoluminescent properties with porous features.•The illumination color and intensity were facilely tuned.Mesostructured and mesoporous materials are emerging as a new class of optical materials. However, their synthesis is nontrivial. In this work, periodic mesostructured metal complex-containing silicas of MCM- and SBA-type bearing homogeneously distributed photoluminescent tri(8-quinolinolato)aluminum inside the channel walls (denoted as Alq3@PMO-MCM and Alq3@PMO-SBA, respectively) have been achieved via one-pot co-assembling of inorganic/surfactant/optically active species. A comprehensive multianalytical characterization of the structural and optical properties demonstrates that both Alq3@PMO-MCM and Alq3@PMO-SBA series gainfully combine the photoluminescent properties of Alq3 with the porous features of PMOs. Regularly arranged pores provide high surface area to disperse optically active components well and render Alq3-containing PMOs promising materials for optoelectronic applications.Graphical abstract

Engineering metal–organic frameworks immobilize gold catalysts for highly efficient one-pot synthesis of propargylamines

Co-reporter:Liu Lili, Zhang Xin, Gao Jinsen and Xu Chunming

Green Chemistry 2012 vol. 14(Issue 6) pp:1710-1720

Publication Date(Web):21 Mar 2012

DOI:10.1039/C2GC35284B

Engineering metal–organic frameworks (MOF) for heterogeneous catalysts have been of extreme interest since they could bridge the gap between homogeneous and heterogeneous catalysis. We have designed and synthesized gold functionalized IRMOF-3 catalysts by post-covalent modification (PM) and one-pot (OP) synthesis methods. The gold functionalized IRMOF-3 catalysts provide an efficient, economic, and novel route for the one-pot synthesis of structurally divergent propargylamines via three component coupling of alkyne, amine, and aldehyde (A3) without any additives or an inert atmosphere. The catalysts were characterized in depth to understand their structure–property relationship. It was shown that the 4.6%Au/IRMOF-3 catalyst, prepared by the PM method, contains a fraction of cationic gold (Au3+/Au0 = 0.2), which shows much higher catalytic activity than that of 3.2% or 0.6%Au/IRMOF-3 prepared by OP method, although the former exhibits much lower crystallinity than the latter two catalysts. Notably, the catalytic activity of the Au/IRMOF-3 catalysts could be significantly enhanced at a moderate reaction temperature (150 °C). All the Au/IRMOF-3 catalysts can be easily recycled and used repetitively at least 5 times, especially the catalysts prepared by the OP method, which showed no drop in activity for the successive 5 uses. These features render the catalysts particularly attractive in the practice of propargylamines synthesis in an environmentally friendly manner.

Glycine-Mediated Syntheses of Pt Concave Nanocubes with High-Index {hk0} Facets and Their Enhanced Electrocatalytic Activities

Co-reporter:Zhi-cheng Zhang, Jun-feng Hui, Zhi-Chang Liu, Xin Zhang, Jing Zhuang, and Xun Wang

Langmuir 2012 Volume 28(Issue 42) pp:14845-14848

Publication Date(Web):October 9, 2012

DOI:10.1021/la302973r

Metal nanocrystals with high-index facets (HIFs) have drawn significant attention for their superior catalysis activity compared to that of low-index faces. However, because of the high surface energy of HIFs, it is still challenging to preserve HIFs during the growth of nanocrystals. In this study, highly selective Pt concave nanocubes (CNCs) with high-index {hk0} facets have been successfully prepared in a simple aqueous solution. The vital role of glycine as the surface controller in the formation of CNCs was demonstrated. These Pt CNCs exhibited enhanced specific activities toward the electro-oxidation of methanol and formic acid in comparison to commercial Pt black and Pt/C catalysts.

Pd Cluster Nanowires as Highly Efficient Catalysts for Selective Hydrogenation Reactions

Co-reporter:Dr. Zhi-Cheng Zhang;Dr. Xin Zhang;Dr. Qi-Yu Yu;Dr. Zhi-Chang Liu;Dr. Chun-Ming Xu; Jin-Sen Gao;Dr. Jing Zhuang;Dr. Xun Wang

Chemistry - A European Journal 2012 Volume 18( Issue 9) pp:2639-2645

Publication Date(Web):

DOI:10.1002/chem.201102903

Abstract

Palladium is a key catalyst invaluable to many industrial processes and fine-chemical synthesis. Although recent progress has allowed the synthesis of Pd nanoparticles with various shapes by using different techniques, the facile synthesis of Pd nanocrystals and turning them into a highly active, selective, and stable catalyst systems still remain challenging. Herein, we report the highly selective one-pot synthesis of monodisperse Pd cluster nanowires in aqueous solution; these consist of interconnected nanoparticles and may serve as highly active catalysts because of the enrichment of high index facets on the surface, including {443}, {331}, and {221} steps. For the first time, carbon nanotube and γ-Al₂O₃ immobilized Pd cluster nanowires showed highly enhanced catalytic performance in the liquid-phase selective hydrogenation of cinnamaldehyde and gas-phase hydrogenation of 1,3butadiene relative to immobilized Pd icosahedra and nanocubes, as well as commercial Pd catalysts.

High performance of carbon nanotubes confining gold nanoparticles for selective hydrogenation of 1,3-butadiene and cinnamaldehyde

Co-reporter:Xin Zhang, Yan Cai Guo, Zhi Cheng Zhang, Jin Sen Gao, Chun Ming Xu

Journal of Catalysis (August 2012) Volume 292() pp:213-226

Publication Date(Web):1 August 2012

DOI:10.1016/j.jcat.2012.05.017

This work reports a striking enhancement of catalytic performance of gold nanoparticles (NPs) with average diameter of 3.2 nm partially (ca. 32–40%) confined in the cavity of carbon nanotubes (CNTs) for the gas-phase hydrogenation of 1,3-butadiene (BD), as well as liquid-phase hydrogenation of cinnamaldehyde (CAL). The reaction rates and turnover frequencies of the CNTs confining gold NPs exceed those with a similar size deposited on the outer surface of CNTs and activated carbon by more than one to two orders of magnitude in both two reactions. The selectivity to monobutenes and hydrocinnamaldehyde is up to 100% and 91% at 100% and 95% conversions of BD and CAL, respectively. Au/CNTs catalysts were characterized in depth to establish their structure–property relationship. The peculiar interaction of confined gold NPs with the surface of CNTs facilitates the dissociation/activation of H2, which is the rate-determining step for hydrogenation reactions demonstrated by kinetic studies.Graphical abstractCNTs-confined gold nanoparticles (ca. 3.2 nm) show striking enhancement catalytic performance compared with those located on the outer surface and activated carbon for hydrogenation reactions.Download high-res image (173KB)Download full-size imageHighlights► Au/CNTs with Au nanoparticles of 2–5 nm were prepared by the gold colloid method. ► The ratio of gold nanoparticles filled inside nanotubes to the total was different. ► CNTs-confined Au nanoparticles show high performance for hydrogenation reactions.

Silver nanoparticles encapsulated by metal-organic-framework give the highest turnover frequencies of 105 h−1 for three component reaction by microwave-assisted heating

Co-reporter:Di Li, Xiaoping Dai, Xin Zhang, Hongying Zhuo, Yan Jiang, Yan-Bing Yu, Pengfang Zhang, Xingliang Huang, Hai Wang

Journal of Catalysis (April 2017) Volume 348() pp:276-281

Publication Date(Web):1 April 2017

DOI:10.1016/j.jcat.2017.02.013

•Ag@IRMOF-3 nanostructures with tunable sizes of shell and core are prepared by a facile one-pot MW irradiation method.•Ag@IRMOF-3 is highly active for A3 coupling reaction.•The size selective catalysis on Ag@IRMOF-3 is well demonstrated.Microwave (MW)-assisted heating, due to its unique properties has been used for synthesis of metal, oxide, zeolite, and metal-organic framework (MOF), and even to carry out organic reactions. However, less attention has been paid to integration of two or more functional components into advanced materials by MW-assisted strategy. We report herein for the first time for controllable integration of silver nanoparticles (NPs) and IRMOF-3 as a core-shell Ag@IRMOF-3 nanostructures into highly efficient catalysts by a facile one-pot MW irradiation method. Impressively, the uniform core-shell Ag@IRMOF-3 nanostructures can be fabricated as short as 5 min and are highly active for three-component coupling reaction of amine, aldehyde and acetylene (A3-coupling) by MW-assisted heating strategy. Specifically, the Ag@IRMOF-3 with average size of Ag NPs of 5.2 nm and IRMOF-3 of 91.5 nm exhibited the highest turnover numbers and turnover frequencies of 3052 and 149,004 h−1 reported up to date, respectively, for the A3-coupling reaction. Thanks to the MOF shell coating, the Ag@IRMOF-3 can be recycled at least for 8 runs without losing any activity; furthermore, the size-selective catalysis was also successfully achieved due to the size selective for propargylamines with different sizes.Download high-res image (62KB)Download full-size image

Bimetallic thin film NiCo–NiCoO2@NC as a superior bifunctional electrocatalyst for overall water splitting in alkaline media

Co-reporter:Yun Xiao, Pengfang Zhang, Xin Zhang, Xiaoping Dai, Yangde Ma, Yao Wang, Yan Jiang, Mengzhao Liu and Yue Wang

Journal of Materials Chemistry A 2017 - vol. 5(Issue 30) pp:NaN15912-15912

Publication Date(Web):2017/07/08

DOI:10.1039/C7TA03629A

Non-precious bifunctional electrocatalysts with high water splitting activity are of paramount importance in reducing energy losses in alkaline environments. Herein, we report NiCo–NiCoO2 heterostructures embedded in N-doped carbon (NiCo–NiCoO2@NC) as an efficient bifunctional catalyst for overall water splitting in alkaline media. Partially reduced nickel and cobalt interfaced with nickel cobalt oxide result from thermal decomposition of nickel cobalt double hydroxide precursors encapsulated in high surface area carbon. Bimetallic thin film NiCo–NiCoO2@NC exhibits a synergy of two active metals – Ni and Co, achieving remarkably small onset potentials of 0 and 200 mV, and overpotentials of 94 and 318 mV at 10 mA cm−2 for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, and achieving TOFs at η = 500 mV more than 2-fold of Pt/C in the HER and IrO2 in the OER. Momentously, a water electrolyzer that achieves 20 mA cm−2 at a voltage of 1.44 V is fabricated by utilizing cheap non-precious NiCo–NiCoO2@NC as anode and cathode catalysts simultaneously. Thanks to the protective carbon coating and the mutual aid of Ni–Co alloy and NiCoO2, NiCo–NiCoO2@NC maintains 20 mA cm−2 for at least 50 h in alkaline media without trivial activity losses. The prominent synergetic and structural effects have been extensively discussed to shed light on the overall water splitting electrocatalyst design.

Microwave-assisted synthesis of multiply-twinned Au–Ag nanocrystals on reduced graphene oxide for high catalytic performance towards hydrogen evolution reaction

Co-reporter:Yuchen Qin, Xiaoping Dai, Xin Zhang, Xingliang Huang, Hui Sun, Daowei Gao, Yanbing Yu, Pengfang Zhang, Yan Jiang, Hongying Zhuo, Axiang Jin and Hai Wang

Journal of Materials Chemistry A 2016 - vol. 4(Issue 10) pp:NaN3871-3871

Publication Date(Web):2016/02/10

DOI:10.1039/C5TA10428A

Nanocrystals (NCs) with a multiply-twinned structure possess great potential in the field of electrocatalysis. Reduced graphene oxide (rGO) has been employed as a support to further improve the stability and activity of catalysts. However, the twinned structure is thermodynamically unstable due to the high total free energy, and it is difficult to control the shape of the crystals during preparation, especially when grown directly on the surface of rGO. Herein, multiply-twinned structural Au–Ag decahedra and icosahedra were grown directly in situ on rGO through a facile approach under microwave irradiation. Thanks to the synergy of abundant twin defects and the electronic effect of the intimate contact/interaction between the Au–Ag alloy and the rGO, these as-prepared Au–Ag NCs/rGO hybrids exhibit excellent activity and stability towards the hydrogen evolution reaction. In particular, Au–Ag icosahedra/rGO exhibits Pt-like electrocatalytic activity and enhanced stability compared to commercial Pt/C.

Platinum–cobalt nanocrystals synthesized under different atmospheres for high catalytic performance in methanol electro-oxidation

Co-reporter:Yuchen Qin, Xin Zhang, Xiaoping Dai, Hui Sun, Ying Yang, Qingxiao Shi, Daowei Gao and Hai Wang

Journal of Materials Chemistry A 2015 - vol. 3(Issue 20) pp:NaN10676-10676

Publication Date(Web):2015/04/09

DOI:10.1039/C5TA01950H

Pt–Co nanocrystals with cube, dendrite and sphere shapes have been fabricated in air, hydrogen and nitrogen, respectively, at ambient pressure or 1 MPa. The Pt–Co nanocrystals with a chain-like structure, synthesized in nitrogen at 1 MPa, exhibited superior electrocatalytic activity and stability towards the methanol oxidation reaction.

Self-assembly of monodispersed hierarchically porous Beta-SBA-15 with different morphologies and its hydro-upgrading performances for FCC gasoline

Co-reporter:Daowei Gao, Aijun Duan, Xin Zhang, Kebin Chi, Zhen Zhao, Jianmei Li, Yuchen Qin, Xilong Wang and Chunming Xu

Journal of Materials Chemistry A 2015 - vol. 3(Issue 32) pp:NaN16512-16512

Publication Date(Web):2015/07/08

DOI:10.1039/C5TA03671B

Micro-mesoporous Beta-SBA-15 materials with platelet, sphere, short-rod and long-rod morphologies were in situ synthesized and used as the catalyst supports for hydro-upgrading of FCC gasoline. The characterization results revealed that the Beta-SBA-15 composites possessed both SBA-15 and Beta structures. And the materials with different morphologies exhibited different Brönsted and Lewis acid sites and pore sizes due to their corresponding synthesis conditions. The platelet Beta-SBA-15 which possessed short mesochannels with a large pore diameter had high diffusion ability. The sphere Beta-SBA-15 with more mesopore cavities, large surface area and suitable acidity exhibited outstanding isomerization and aromatization abilities. The catalytic results confirmed that the platelet CoMo/ABS-PL exhibited a high hydrodesulfurization (HDS) conversion (97.6%) while the sphere CoMo/ABS-SP catalyst showed the superior research octane number (RON) preservation ability, which were better than those of CoMo/ABS-SR (short-rod) and CoMo/ABS-LR (long-rod) catalysts. The excellent hydrodesulfurization, isomerization and aromatization abilities of CoMo/ABS-PL and CoMo/ABS-SP were attributed to the special morphology, mesochannels and appropriate acidity properties of the catalysts. Thus, the as-synthesized platelet and sphere Beta-SBA-15 materials have potential application in FCC gasoline hydro-upgrading.

Highly stable and active PtNiFe dandelion-like alloys for methanol electrooxidation

Co-reporter:Zhenguo Guo, Xiaoping Dai, Ying Yang, Zhicheng Zhang, Xin Zhang, Shiqi Mi, Kai Xu and Yongfeng Li

Journal of Materials Chemistry A 2013 - vol. 1(Issue 42) pp:NaN13260-13260

Publication Date(Web):2013/08/16

DOI:10.1039/C3TA12894F

Novel PtNiFe dandelion-like alloys are fabricated by a facile etching strategy. The ternary alloys and single-walled carbon nanotube (SWNT) immobilized PtNiFe alloys exhibit high activity and poison tolerance with remarkable stability for methanol oxidation reaction (MOR). The excellent electro-catalytic performance is ascribed to the unique dandelion-like nanostructure.

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