Electrochemical coupling hydrogen evolution with biomass reforming reaction (named electrochemical hydrogen and chemical cogeneration (EHCC)), which realizes green hydrogen production and chemical upgrading simultaneously, is a promising method to build a carbon-neutral society. Herein, we analyze the EHCC process by considering the market assessment. The ethanol to acetic acid and hydrogen approach is the most feasible for large-scale hydrogen production. We develop AuCu nanocatalysts, which can selectively oxidize ethanol to acetic acid (> 97%) with high long-term activity. The isotopic and in-situ infrared experiments reveal that the promoted water dissociation step by alloying contributes to the enhanced activity of the partial oxidation reaction path. A flow-cell electrolyzer equipped with the AuCu anodic catalyst achieves the steady production of hydrogen and acetic acid simultaneously in both high selectivity (> 90%), demonstrating the potential scalable application for green hydrogen production with low energy consumption and high profitability.

The impeded mass transfer rate by on-site-generated gas bubbles at both cathode and anode dramatically reduces the energy conversion efficiency of the proton exchange membrane water electrolyzer (PEMWE). Herein, we report a surfactant-assistant method to accelerate the nano/micro-bubble detachment and the mass transfer rate by reducing the surface tension, resulting in an increase in overall efficiency. Four kinds of surfactants are studied in this work. Only potassium perfluorobutyl sulfonate (PPFBS), which has the structural similarity to Nafion, shows a significant promotion of activity and stability for both hygrogen evolution reaction (HER) and oxygen evolution reaction (OER) in the acidic medium at the high current density region. The HER overpotential at 0.1 A·cm⁻² decreased 22%, and the current density at −0.4 V increased 31% by adding PPFBS. The promotion of overall efficiency by PPFBS on a homemade PEMWE was also proven. The reduced surface tension and electrostatic repulsion were the probable origins of the accelerated bubble detachment.

Ag is a potential low-cost oxygen reduction reaction (ORR) catalyst in alkaline condition, which is important for the zinc-air batteries. Here, we report that an Ag based single atom catalyst with heteroatom coordination. Ag₁-h-NPClSC, has been synthesized and shown much improved performance towards ORR by manipulating the coordination environment of the Ag center. It shows a high half wave potential (0.896 V) and a high turnover frequency (TOF) (5.9 s⁻¹) at 0.85 V, which are higher than the previously reported Ag based catalysts and commercial Pt/C. A zinc-air battery with high peak power density of 270 mW·cm⁻² is fabricated by using the Ag₁-h-NPClSC as air electrode. The high performance is attributed to (1) the hollow structure providing good mass transfer; (2) the single atom metal center structure providing high utility of the Ag; (3) heteroatom coordination environment providing the adjusted binding to the ORR intermediates. Density functional theory (DFT) calculations show that the energy barrier for the formation of OOH*, which is considered as the rate determine step for ORR on Ag nanoparticles, is lowered on Ag₁-h-NPClSC, thus improving the ORR activity. This work demonstrates that the well manipulated Ag based single atom catalysts are promising in electrocatalysis.

Electrochemical upgrading of biomass ethanol to value-added chemicals is promising for sustainable society. Here, we synthesize defective Ni₃S₂ nanowires (NWs), which show high activity towards electrochemical oxidation of ethanol to acetate. The Ni₃S₂ NWs are formed by the oriented attachment mechanism, and rich defects are introduced during the growth. A low onset potential of 1.31 V and high mass activity of 8,716 mA·mg_Ni⁻¹ at 1.5 V are achieved using the synthesized Ni₃S₂ NWs toward the ethanol electro-oxidation, which are better than the Ni(OH)₂ NWs and the Ni₃S₂ nanoparticles (NPs). And the selectivity for the acetate generation is ca. 99%. The high activity of Ni₃S₂ NWs is attributed to the easier oxidation of Ni(II) to the catalytically active Ni(III) species with the promotion from S component and rich defects. These results demonstrate that the defective NWs can be synthesized by the oriented attachment method and the defective Ni₃S₂ NWs structure as the efficient non-noble metal electrocatalysts for oxidative upgrading of ethanol.