A Janus Fe-SnO2 Catalyst that Enables Bifunctional Electrochemical Nitrogen Fixation

Electrochemical N-2 reduction reactions (NRR) and the N-2 oxidation reaction (NOR), using H2O and N-2, are a sustainable approach to N-2 fixation. To date, owing to the chemical inertness of nitrogen, emerging electrocatalysts for the electrochemical NRR and NOR at room temperature and atmospheric pressure remain largely underexplored. Herein, a new-type Fe-SnO2 was designed as a Janus electrocatalyst for achieving highly efficient NRR and NOR catalysis. A high NH3 yield of 82.7 mu g h(-1) mg(cat.)(-1) and a Faraday efficiency (FE) of 20.4 % were obtained for NRR. This catalyst can also serve as an excellent NOR electrocatalyst with a NO3- yields of 42.9 mu g h(-1) mg(cat.)(-1) and a FE of 0.84 %. By means of experiments and DFT calculations, it is revealed that the oxygen vacancy-anchored single-atom Fe can effectively adsorb and activate chemical inert N-2 molecules, lowering the energy barrier for the vital breakage of N equivalent to N and resulting in the enhanced N-2 fixation performance.