Coupling Value-Added Methanol Oxidation with CO₂ Electrolysis by Low-Coordinated Atomic Ni Sites.

Abstract

The combination of CO₂ fixation and small organic molecule oxidation offers a promising solution to increasing severe environmental issues and energy crises. Here, low-coordinated NiN₃ sites were anchored onto nitrogen-doped ordered mesoporous carbon (Ni-SAs/NOMC), which is capable of efficiently catalyzing the coupled methanol oxidation reaction and CO₂ reduction reaction (MOR||CO₂RR), thereby reducing the energy required for CO₂ conversion and enhancing the economic value of the CO₂ electrolytic system. In the membrane electrode assembly electrolyzer-based MOR||CO₂RR, Ni-SAs/NOMC achieved Faradaic efficiencies (FEs) of 95.4% for formate at the anode and 96.3% for CO at the cathode. Moreover, at a current density of 0.8 A cm^-2, Ni-SAs/NOMC demonstrated stable electrolysis for up to 100 h, with FEs at both the anode and cathode remaining stable at approximately 90%. In situ spectroscopy analyses and theoretical calculations identified the formation of critical intermediate species and the origin of activity improvement, guiding the development of efficient electrosynthesis of valuable chemicals.