College of Chemistry and Chemical Engineering Institution Qingdao University, Qingdao, 266071, Shandong, P. R. China.
State Key Laboratory of Fine Chemicals, Dalian University of Technology (DUT), Dalian, 116024, Liaoning, P. R. China.
Angew Chem Int Ed Engl. 2023 Mar 20;62(13):e202217635. doi: 10.1002/anie.202217635. Epub 2023 Feb 20.
Atomically dispersed Fe was designed on TiO and 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 g and 12 868.33 μmol h g 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 N fixation performance. More importantly, PE could effectively enhance the N supply by reducing competitive O and H agglomeration, inhibit the electrocatalytic by-product formation for longstanding *OOH and *H intermediates, and promote the non-electrocatalytic process of N activation.
在两电极体系中，原子分散的 Fe 被设计在 TiO 上，作为氮氧化反应 (NOR) 和氮还原反应 (NRR) 的双功能电催化剂进行了探索。首先引入脉冲电化学催化 (PE) 以抑制竞争析氢反应 (HER) 和析氧反应 (OER)。令人兴奋的是，在 3.5 V 下，NOR 和 NRR 的产率分别达到了 7055.81 μmol h g 和 12 868.33 μmol h g，分别比传统恒压电催化方法提高了 44.94 倍和 7.8 倍。实验和密度泛函理论 (DFT) 计算表明，单原子 Fe 可以稳定氧空位，降低 N≡N 键关键断裂的能垒，从而提高氮固定性能。更重要的是，PE 可以通过减少竞争 O 和 H 聚集来有效增强 N 供应，抑制析氧和析氢中间产物 *OOH 和 *H 的电催化生成，促进 N 激活的非电催化过程。
