Zn‐Nx Doping in Carbon Nanotubes Boosts Selective CO2 Electroreduction to CO

Abstract Electroreduction of CO 2 to CO is attractive target to store energy from intermittent sources, as it requires the transfer of only two electrons and two protons. Metal‐based catalysts (Au, Ag, Ni, Fe, etc.), especially metal‐ and N‐co‐doped carbon materials have been proven to show high selectivity for CO production. However, for Zn‐based catalysts, the critical active site is still intensely debated. Herein, we synthesize a series of carbon nanotube‐supported Zn‐based catalysts with a tunable ratio of isolated ZnN x sites and Zn‐based nanoparticles. We identify ZnN x moieties anchored on the surface of carbon nanotubes are catalytically highly active for the selective CO 2 electroreduction to CO, with the Faradaic efficiency (FE) as high as 97.3 %. In contrast, N‐doped carbon nanotubes (NCNTs) and Zn‐containing nanoparticles supported on NCNTs exhibit inferior selectivity with the CO FEs of 56.7 % and 72.9 %, respectively, suggesting that Zn doping in carbon and the existing forms are of significant importance for improving the ability of Zn‐based catalysts for electrocatalytic reduction of CO 2 .