An Innovative Approach to Precisely Tailor the Composition of Syngas in CO Electroreduction.

Syngas production through CO electrochemical reduction reaction (CORR) has attracted numerous attention for reducing carbon emissions and increasing chemical feedstocks. However, the precise regulation of H/CO molar ratio in syngas remains a challenge, especially through simple and feasible methodologies. In this work, a novel composite electrocatalyst, copper-indium/black phosphorus (CuIn/BP) is developed, using a simple one-step co-reduction method for efficient CORR. It is found for the first time that there is a linear relationship between BP content in CuIn/BP and the H/CO molar ratio in syngas. Consequently, the H/CO molar ratio in syngas can be precisely tailored by simply adjusting the BP content in CuIn/BP. A total faradaic efficiency (FE) of CO and H reached ≈ 100% along with a current density of 135.2 mA cm. Mechanistic studies suggest that the CuIn phase and CuP species are in situ generated in CuIn/BP, where the CuIn phases mainly contribute to CO generation, while the CuP species promote H formation. The variation in BP content modulates the proportion of the CuIn phase and CuP species, leading to the variations in H/CO molar ratios. Thus, this study provides an efficient and simple strategy to tailor the H/CO molar ratio in syngas for various industrial applications.