Cu single-atom catalysts could be promising non-noble catalysts towards oxygen reduction for fuel cell applications.

Carbohydrazide is a potential alternative to toxic hydrazine for fuel cell applications to overcome the challenges of storage and transportation of hydrogen. In this work, Ni‐alloyed Pd nanoparticles (NPs) with varied Pd–Ni ratios supported on carbon black (PdNix/C) are prepared and their catalytic performance for the carbohydrazide electro‐oxidation reaction is investigated. The catalytic performance of PdNix/C NPs is significantly improved in comparison to Pd/C NPs. The current density of PdNix/C NPs with optimized Pd–Ni atom ratio can reach 3.26 A mg−1metal at a potential of 0.4 V (vs reversible hydrogen electrode), which is an increase of 2.4 times compared to that of Pd/C. The density functional theory calculation indicates the enhanced catalytic activity is caused by the change of adsorption energy of carbohydrazide molecules on the metal surface. It exhibits a volcano relationship between the adsorption energy and the catalytic current density of PdNix/C with varied Pd–Ni atom ratios.

It is of great significance to reduce the amount of platinum for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells. In this work, a copper single atom coordinated by nitrogen doped carbon nanotubes is employed as a support for the deposition of platinum nanoparticles (Pt/Cu-SAC), according to the prediction of the density functional theory calculation, which reveals the ORR activity of Pt/Cu-SAC should be improved in comparison to that of Pt/C due to the weaker adsorption of oxygen. The prepared Pt/Cu-SAC exhibits more promising ORR activity than the commercial Pt/C due to the synergetic effect of Cu-SAC on the Pt particles. Furthermore, the fuel cell based on Pt/Cu-SAC with a cathode Pt loading of 0.025 mg cm −2 exhibits a peak power density of 526 mW cm −2 , which is quite similar to that obtained with the commercial Pt/C with a cathode Pt loading of 0.1 mg cm −2 . The Pt/Cu-SAC paves the way to design low-Pt cathode catalysts for the polymer electrolyte membrane fuel cells.

N,S co-doped hierarchical nanocarbon derived from an azo-sulphonate dye pollutant demonstrates superior catalytic activity for the reduction of nitroarenes.

An efficient model containing only 7 metal atoms was proposed to describe the ORR activity of metal catalysts by DFT calculation.