Unlocking direct CO2 electrolysis to C3 products via electrolyte supersaturation

The electroreduction of CO2 has recently achieved notable progress in the formation of C-2 products such as ethylene and ethanol. However, the direct synthesis of C-3 products is considerably limited by the C-2-C-1 coupling reaction and the faradaic efficiency has remained low. Here we present a supersaturation strategy for the electrosynthesis of 2-propanol from CO2 in highly carbonated electrolytes. By controlling the CO2 concentration above the saturation limit, we have developed a co-electrodeposition method with suppressed galvanic replacement to obtain a CuAg alloy catalyst. In supersaturated conditions, the alloy achieved high performance for the production of 2-propanol with a faradaic efficiency of 56.7% and at a specific current density of 59.3 mA cm(-2). Our investigations revealed that the presence of dispersed Ag atoms in Cu weakens the surface binding of intermediates in the middle position of the alkyl chain and strengthens the C-O bonds, which favours the formation of 2-propanol over 1-propanol.

Automated summary

A supersaturation strategy was employed to electrosynthesize 2-propanol from CO2 using highly carbonated electrolytes. The CuAg alloy catalyst exhibited high performance for 2-propanol production with a faradaic efficiency of 56.7% and at a specific current density of 59.3 mA cm(-2).