Toward Highly Selective Electrochemical CO2 Reduction using Metal‐Free Heteroatom‐Doped Carbon

摘要

There are growing interests in metal‐free heteroatom‐doped carbons for electrochemical CO2 reduction. Previous studies extensively focus on the effect of N‐doping, and their products severely suffer from low current density (mostly 2?mA cm?2) and limited selectivity (90%). Here, it is reported that heteroatom codoping offers a promising solution to the above challenge. As a proof of concept, N,P‐codoped mesoporous carbon is prepared by annealing phytic‐acid‐functionalized ZIF‐8 in NH3. In CO2‐saturated 0.5 m NaHCO3, the catalyst enables CO2 reduction to CO with great selectivity close to 100% and large CO partial current density (≈8?mA cm?2), which are, to the best of knowledge, superior to all other relevant competitors. Theoretical simulations show that the improved activity and selectivity are stemmed from the enhanced surface adsorption of *COOH and *CO intermediates as a result of the synergy of N and P codoping.