Boosting CO₂ Electroreduction on N,P-Co-doped Carbon Aerogels

Electroreduction of CO₂ to CO powered by renewable electricity is a possible alternative to synthesizing CO from fossil fuel. However, it is very hard to achieve high current density at high faradaic efficiency (FE). Here, the first use of N,P-co-doped carbon aerogels (NPCA) to boost CO₂ reduction to CO is presented. The FE of CO could reach 99.1 % with a partial current density of −143.6 mA cm⁻², which is one of the highest current densities to date. NPCA has higher electrochemical active area and overall electronic conductivity than that of N- or P-doped carbon aerogels, which favors electron transfer from CO₂ to its radical anion or other key intermediates. By control experiments and theoretical calculations, it is found that the pyridinic N was very active for CO₂ reduction to CO, and co-doping of P with N hinder the hydrogen evolution reaction (HER) significantly, and thus the both current density and FE are very high.