Pulsed Electrocatalysis Enabling High Overall Nitrogen Fixation Performance for Atomically Dispersed Fe on TiO2

Abstract

AbstractAtomically dispersed Fe was designed on TiO2and explored as a Janus electrocatalyst for both nitrogen oxidation reaction (NOR) and nitrogen reduction reaction (NRR) in a two‐electrode system. Pulsed electrochemical catalysis (PE) was firstly involved to inhibit the competitive hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Excitingly, an unanticipated yield of 7055.81 μmol h−1 g−1cat.and 12 868.33 μmol h−1 g−1cat.were obtained for NOR and NRR at 3.5 V, respectively, 44.94 times and 7.8 times increase in FE than the conventional constant voltage electrocatalytic method. Experiments and density functional theory (DFT) calculations revealed that the single‐atom Fe could stabilize the oxygen vacancy, lower the energy barrier for the vital rupture of N≡N, and result in enhanced N2fixation performance. More importantly, PE could effectively enhance the N2supply by reducing competitive O2and H2agglomeration, inhibit the electrocatalytic by‐product formation for longstanding *OOH and *H intermediates, and promote the non‐electrocatalytic process of N2activation.