Acidic CO electroreduction for high CO utilization: catalysts, electrodes, and electrolyzers.

The electrochemical carbon dioxide (CO) reduction reaction (CORR) is considered a promising technology for converting atmospheric CO into value-added compounds by utilizing renewable energy. The CORR has developed in various ways over the past few decades, including product selectivity, current density, and catalytic stability. However, its commercialization is still unsuitable in terms of economic feasibility. One of the major challenges in its commercialization is the low single-pass conversion efficiency (SPCE) of CO, which is primarily caused by the formation of carbonate (CO) in neutral and alkaline electrolytes. Notably, the majority of CORRs take place in such media, necessitating significant energy input for CO regeneration. Therefore, performing the CORR under conditions that minimize CO formation to suppress reactant and electrolyte ion loss is regarded an optimal strategy for practical applications. Here, we introduce the recent progress and perspectives in the electrochemical CORR in acidic electrolytes, which receives great attention because of the inhibition of CO formation. This includes the categories of nanoscale catalytic design, microscale microenvironmental effects, and bulk scale applications in electrolyzers for zero carbon loss reactions. Additionally, we offer insights into the issue of limited catalytic durability, a notable drawback under acidic conditions and propose guidelines for further development of the acidic CORR.