The current work introduces highly dispersed Pt and PtSn catalysts supported on La2O2CO3 nanorods prepared via ultrasonic impregnation, which are used as probe catalysts for the liquid-phase crotonaldehyde hydrogenation. The physicochemical properties of the catalysts are assessed by means of various techniques, including XRD, TEM, XPS, H2-TPD, in situ CO-DRIFT and X-ray adsorption fine structure (XAS). A close combination of catalyst surface experiments and the reactive performances reveals that the distinct reactive performance of the Pt and PtSn catalysts is tentatively attributed to the composition-dependent architecture of Pt–lanthanum interfaces and bimetallic particles while excluding the particle size effect. Catalytic activity tests demonstrate that incorporation of Sn into Pt catalyst brings great significance to the selective hydrogenation of carbonyl groups as it results into the structure evolution of bimetallic particles. An optimization of Sn loading and reaction conditions achieves a 5-fold and 7-fold improvement in the selectivity and yield to crotyl alcohol over the parent Pt catalyst. Lastly, it is found from the catalyst reusability study that metal particles of PtSn catalysts suffers easily from particle migration and growth compared to the Pt catalyst, most likely resulting from a weaker metal–support interaction.

Rod-like and particle-like La2O2CO3 and La2O3 were obtained via morphology-preserved thermal transformation of the La(OH)3 precursors. La2O2CO3- and La2O3-supported Pt catalysts were prepared by impregnation method and tested in the liquid-phase crotonaldehyde hydrogenation reaction. The textural and physicochemical properties of the samples were studied by a series of techniques including XRD, TG-DSC, N2 adsorption–desorption, TEM and HRTEM, IR spectrum, H2-TPD, and H2-TPR. Even after 600 °C reduction, Pt particles of about 0.8–2.8 nm interplayed with support surface to form Pt-doped interface, thereby preventing the catalysts from migration and affording a high dispersion of platinum. The specific exposed crystal-facets and surface oxygen species depending on the shape of the support affected the preferential deposition of Pt species and the metal-support interaction. Thus, Pt catalysts performed different physicochemical properties and catalytic performance relying on the morphology and structure of the supports. During the cycle experiment, severe deactivation was observed for NP-supported catalysts with an increased selectivity due to the aggregation and growth of Pt particles. Meantime, the NR-supported catalysts retained relatively high reactivity as a consequence of the crystal-facet confinement of rod-shaped lanthanum supports.

•The cylindrical MOF-5-BPO crystals were firstly synthesized by BPO.•The pore volumes of MOF-5-BPO were 0.84–1.07 cm3 g−1, higher than that of MOF-5-H2O2.•The concentration of BPO was critical for the pore texture of MOF-5-BPO.•MOF-5-BPO could store 1.24 wt% H2 at 77 K and 100 KPa.In this study, for the first time, the uniform cylindrical MOF-5-BPO (Zn4O(BDC)3(H2O)·0.5ZnO, BDC = 1,4-benzenedicarboxylate, BPO = benzoyl peroxide) crystals with large Brunauer–Emmett–Teller (BET) surface area (3210.2 m2 g−1) was successfully synthesized by room temperature synthesis in the presence of BPO using zinc nitrate hexahydrate (Zn(NO3)2·6H2O) as the zinc source. The pore volumes of MOF-5-BPO materials prepared with different concentrations of BPO were 0.84–1.07 cm3 g−1, higher than that of MOF-5-NP (0.68 cm3 g−1, Zn4O(BDC)3(H2O)3·2ZnO) and MOF-5-H2O2 (0.84 cm3 g−1, Zn4O(BDC)3(H2O)2·2ZnO, H2O2 = hydrogen peroxide). The addition of the peroxides created new pores, which possessed the same diameters as the existing ones, thus increased the pore volume of the product. The concentration of BPO was critical for the pore texture of MOF-5-BPO. Moreover, MOF-5-BPO could store 1.24 wt% hydrogen at 77 K and 100 kPa. Thus, this study points out some information for one to realize the influence of the peroxides over MOF-5 structure and promises the potentiality of large-scale production of MOF-5 structure with large surface area.

•Cd modified TS-1 were used as catalysts for butadiene epoxidation.•The addition of Cd significantly promoted vinyloxirane yield and H2O2 utilization.•Quantum chemical calculations were used to explore detailed Cd roles in TS-1.•Five-membered cyclic intermediate formation was facilitated for Cd modification.•Active O eletrophilicity in H2O2 was promoted for Cd modification.A series of Cd modified titanium silicalite 1 catalysts with different Cd content (xCd-TS-1, x = 1–15) were successfully prepared by ultrasound impregnation. Epoxidation of butadiene over these catalysts were investigated using hydrogen peroxide as oxidant, which indicated that Cd greatly improve the catalytic performance of TS-1 and the selectivity of epoxide. Various characterization methods including quantum chemical calculation were employed to explore the specific roles of Cd in promoting TS-1 catalytic activity. Theoretical calculation consistently suggested TiO bond were weakened owing to the introduction of Cd, which resulted in the structure of Cd-TS-1 becoming more relaxant. As a consequence, it is favorable to methanol solvent and H2O2 interacting with the Ti active site to form five-member transition state during reaction. It was observed that catalysts modified with 1–5 wt% Cd presented both high catalytic activity and good reusability. The highest yield of 0.63 mol/L of vinyloxirane (VO) was obtained, while turnover number (TON, determined as the molar VO obtained per molar Ti atom) could reach to 1466.Epoxidation of butadiene to vinyloxirane were carried out over Cd modified TS-1 catalysts. The additive of Cd provided more chances for CH3OH and H2O2 to approach the Ti active sites and hence facilitated the formation of five-membered cyclic intermediate. Moreover, O of H2O2 close to Ti in five-membered intermediate was activated with promoted eletrophilicity by Cd modification.

Nickel modified Titanium silicalite 1 (TS-1) catalysts provided an environmentally benign and effective method for butadiene epoxidation. Certain loading of modified Ni in our system significantly promoted TS-1 catalytic activity. The product vinyloxirane (VO) was obtained with high yield of 0.49 mol/L (theoretic equilibrium value 0.52 mol/L). The turnover number (TON, determined as the molar VO obtained per molar Ti atom) reached 1,140. Besides, the catalyst kept high activity during five runs of reusability test. XRD, N2 adsorption and desorption, TPR, XPS, FT-IR and DR UV–Vis were employed to characterize the specific Ni role to Ti-site in Ni/TS-1 catalysts.