Engineering Reaction Pathway to Harmonize the Competition between NRR and HER for Efficient Photocatalytic Ammonia Synthesis
Zhanfeng Zhao, Yao Nian, Jiafu Shi, Xin Xin, Xinyuan Huang, Yonghui Shi, Jiangdan Tan, Yue Zhang, You Han, Dong Yang, Zhongyi Jiang
Abstract
Engineering a reaction pathway to harmonize the competition between nitrogen reduction reaction (NRR) and hydrogen evolution reaction (HER) is an active strategy toward efficient ammonia synthesis. Herein, we insert a “hydrogen state switching” reaction between the NRR and HER in ammonia synthesis. H 2 from HER in NH 2 -MIL125 core is captured by the Ni nanoparticles on polydopamine shell and switched into adsorbed-state *H species, which are then transferred back to NH 2 -MIL125 core via NiO to react with nitrogen and produce NH 3 . By manipulating the reaction pathway of hydrogen generation-state switching-transfer-utilization, HER can supply the required hydrogen for NRR. Accordingly, our photocatalyst achieved the NH 3 yield and selectivity of 817 μmol g –1 h –1 and 99.8% in NRR, respectively, superior to those of most state-of-the-art photocatalysts. Our strategy, as “transforming-competition-into-cooperation” strategy, is applicable for many complex reaction systems.