The synergistic effect between Pt and WC is beneficial for methanol electro-oxidation, and makes Pt–WC catalyst a promising anode candidate for the direct methanol fuel cell. This paper reports on the design and synthesis of small-sized and contacting Pt–WC nanostructures on graphene that bring the synergistic effect into full play. Firstly, DFT calculations show the existence of a strong covalent interaction between WC and graphene, which suggests great potential for anchoring WC on graphene with formation of small-sized, well-dispersed WC particles. The calculations also reveal that, when Pt attaches to the pre-existing WC/graphene hybrid, Pt particles preferentially grow on WC rather than graphene. Our experiments confirmed that highly disperse WC nanoparticles (ca. 5 nm) can indeed be anchored on graphene. Also, Pt particles 2–3 nm in size are well dispersed on WC/graphene hybrid and preferentially grow on WC grains, forming contacting Pt–WC nanostructures. These results are consistent with the theoretical findings. X-ray absorption fine structure spectroscopy further confirms the intimate contact between Pt and WC, and demonstrates that the presence of WC can facilitate the crystallinity of Pt particles. This new Pt–WC/graphene catalyst exhibits a high catalytic efficiency toward methanol oxidation, with a mass activity 1.98 and 4.52 times those of commercial PtRu/C and Pt/C catalysts, respectively.

Carbide-based electrocatalysts are superior to traditional carbon-based electrocatalysts, such as the commercial Pt/C electrocatalysts, in terms of their mass activity and stability. Herein, we report a general approach for the preparation of a nanocomposite electrocatalyst of platinum and vanadium carbide nanoparticles that are loaded onto graphitized carbon. The nanocomposite, which was prepared in a localized and controlled fashion by using an ion-exchange process, was an effective electrocatalyst for the oxygen-reduction reaction (ORR). Both the stability and the durability of the Pt-VC/GC nanocomposite catalyst could be enhanced compared with the state-of-the-art Pt/C. This approach can be extended to the synthesis of other metal-carbide-based nanocatalysts. Moreover, this straightforward synthesis of high-performance composite nanocatalysts can be scaled up to meet the requirements for mass production.

The growth of mesoporous quasi-single-crystalline Co₃O₄ nanobelts by topotactic chemical transformation from α-Co(OH)₂ nanobelts is realized. During the topotactic transformation process, the primary α-Co(OH)₂ nanobelt frameworks can be preserved. The phases, crystal structures, morphologies, and growth behavior of both the precursory and resultant products are characterized by powder X-ray diffraction (XRD), electron microscopy—scanning electron (SEM) and transmission electron (TEM) microscopy, and selected area electron diffraction (SAED). Detailed investigation of the formation mechanism of the porous Co₃O₄ nanobelts indicates topotactic nucleation and oriented growth of textured spinel Co₃O₄ nanowalls (nanoparticles) inside the nanobelts. Co₃O₄ nanocrystals prefer [0001] epitaxial growth direction of hexagonal α-Co(OH)₂ nanobelts due to the structural matching of [0001] α-Co(OH)₂//[111] Co₃O₄. The surface-areas and pore sizes of the spinel Co₃O₄ products can be tuned through heat treatment of α-Co(OH)₂ precursors at different temperatures. The galvanostatic cycling measurement of the Co₃O₄ products indicates that their charge–discharge performance can be optimized. In the voltage range of 0.0–3.0 V versus Li⁺/Li at 40 mA g⁻¹, reversible capacities of a sample consisting of mesoporous quasi-single-crystalline Co₃O₄ nanobelts can reach up to 1400 mA h g⁻¹, much larger than the theoretical capacity of bulk Co₃O₄ (892 mA h g⁻¹).

The selective and simultaneous production of hydrogen and chemicals from renewable alcohols, such as ethanol, glycerol, and ethylene glycol, can be accomplished by means of electrolyzers in which the anode electrocatalyst is appropriately designed to promote the partial and selective oxidation of the alcohol. In the electrolyzers described herein, the production of 1 kg of hydrogen from aqueous ethanol occurs with one-third the amount of energy required by a traditional H₂/O₂ electrolyzer, by virtue of the much lower oxidation potential of ethanol to acetate vs. water to oxygen in alkaline media (E⁰=0.10 V vs. 1.23 V). The self-sustainability of H₂ production is ensured by the simultaneous production of 25 kg of potassium acetate for every kg of H₂, if the promoting co-electrolyte is KOH.