Enhancing selectivity in acidic CO2 electrolysis: Cation effects and catalyst innovation

The electrochemical reduction of CO₂ (eCO₂R) under ambient conditions is crucial for reducing carbon emissions and achieving carbon neutrality. Despite progress with alkaline and neutral electrolytes, their efficiency is limited by (bi)carbonates formation. Acidic media have emerged as a solution, addressing the (bi)carbonates challenge but introducing the issue of the hydrogen evolution reaction (HER), which reduces CO₂ conversion efficiency in acidic environments. This review focuses on enhancing the selectivity of acidic CO₂ electrolysis. It commences with an overview of the latest advancements in acidic CO₂ electrolysis, focusing on product selectivity and electrocatalytic activity enhancements. It then delves into the critical factors shaping selectivity in acidic CO₂ electrolysis, with a special emphasis on the influence of cations and catalyst design. Finally, the research challenges and personal perspectives of acidic CO₂ electrolysis are suggested.