Tuning the Catalytic Selectivity Toward C2+ Oxygenate Products by Manipulating Cu Oxidation States in CO Electroreduction.

Enhancing the reaction selectivity for multicarbon products (C2+) is an important goal for the electrochemical CO(2) reduction (ECO(2)R) process. Cuprous compounds have demonstrated promising C2+ selectivity in the ECO(2)R process, but further investigation is necessary to thoroughly elucidate their catalytic behavior toward C2+ oxygenate production. In this study, copper nitride-based materials with varying reduction rates were employed as precatalysts. Consequently, a relationship between the selectivity toward C2+ oxygenates and the Cu oxidation state during the ECOR process is established. Results of theoretical and experimental analyses reveal that the Cu0/Cu+ interface plays a key role in enhancing *CO adsorption while lowering the formation energy of *CH2CO, thereby promoting acetate production. This work highlights the significance of the Cu0/Cu+ interface in the regulation of C2+ oxygenate production and paves the way for the development of highly selective catalysts in the future.

Interface regulation promoting carbon monoxide gas diffusion electrolysis towards C2+ products.

Electrochemical conversion of carbon dioxide and carbon monoxide into value-added multi-carbon products (C2+) offers a promising approach for artificial oxycarbide recycling. However, C2+ productivity is still limited by gas accessibility inside the catalyst layer. Here, a Cu-PMMA porous hybrid architecture with rich triple-phase boundaries was demonstrated to enhance both gas diffusion and electron transfer, and then, facilitate the kinetics of CO electrolysis. As a result, a high C2+ faradaic efficiency (FE) of 81.6% at a current density of 50 mA cm-2 and a maximum C2+ partial current density of 140 mA cm-2 were achieved, among the best performances for Cu/hybrid catalysts. This study provides a novel strategy for designing electrochemical CO reduction (ECORR) catalysts and paves the way for further developing gas-involving electrocatalysis.

Ruthenium Incorporated Cobalt Phosphide Nanocubes Derived From a Prussian Blue Analog for Enhanced Hydrogen Evolution.

Electrochemical water splitting in alkaline media plays an important role in mass production of hydrogen. Ruthenium (Ru), as the cheapest member of platinum-group metals, has attracted much attention, and the incorporation of trace amount of Ru with cobalt phosphide could significantly improve the hydrogen evolution reaction (HER) catalytic activity. In this work, ruthenium-incorporated cobalt phosphide nanocubes are synthesized via a reaction between Co-Co Prussian blue analog (Co-PBA) and ruthenium chloride (RuCl3) followed by the phosphidation. The sample with a Ru content of ~2.04 wt.% exhibits the best HER catalytic activity with a low overpotential of 51 and 155 mV, to achieve the current densities of -10 and -100 mA cm-2, respectively, and the Tafel slope of 53.8 mV dec-1, which is comparable to the commercial Pt/C. This study provides a new perspective to the design and construction of high performance electrocatalysts for HER and other catalytic applications in a relatively low price.