金属氧化物电催化硝酸盐还原合成氨研究进展

Recent Advances in Electrocatalytic Nitrate Reduction to Ammonia Using Metal Oxides

氨不仅是合成化肥的主要原料之一,而且是一种高能量密度的新型燃料。近年来,电催化硝酸盐还原合成氨作为一种绿色可持续的合成途径,具有能源利用率高、碳排放量低等特点,因此受到了广泛关注,有望替代高能耗和高碳排放的Haber-Bosch法来高效合成氨。然而,目前该技术的反应效率、产物选择性以及催化材料稳定性都难以满足应用需求,迫切需要寻找高效的催化材料,从而促进电催化硝酸盐还原合成氨技术的进一步发展。近年来,金属氧化物催化材料在电催化硝酸盐还原合成氨领域展现出良好的催化性能。基于此,本文综述了金属氧化物电催化硝酸盐还原合成氨的研究进展,重点概述了电催化硝酸盐还原合成氨的反应机理,系统介绍了用于电催化硝酸盐还原合成氨的Cu基、Fe基和Ti基等典型催化材料,以及通过形貌调控、表面重构、氧空位构造、元素掺杂和金属助催化材料负载等策略提高催化反应效率、产物选择性及催化材料稳定性的最新研究进展。最后,展望了电催化硝酸盐还原合成氨领域面临的挑战及未来的研究方向。

Ammonia serves not only as a primary raw material in synthetic fertilizers,but also as a novel high-energy-density fuel.In recent years,electrocatalytic nitrate reduction for ammonia synthesis has gained extensive attention as a green and sustainable approach due to its potential as an eco-friendly and sustainable way that could replace the energy-intensive and high-carbon-emission Haber-Bosch process.Nevertheless,the efficient electrocatalytic ammonia synthesis is still hampered by low reaction efficiency and product selectivity as well as catalyst stability.Hence,there is a pressing need to develop efficient catalysts to advance electrocatalytic nitrate reduction for ammonia synthesis.Recently,metal oxide catalysts have been at the center of attention for their superior performance in electrocatalytic nitrate reduction for ammonia synthesis.This review consolidates the developments of metal oxide electrocatalysts converting nitrate to ammonia,focusing on elucidating the reaction mechanism and introducing typical metal-based(Cu,Fe,Ti,etc.)catalysts.Additionally,it discusses the latest research progress in enhancing catalytic reaction efficiency,product selectivity,and material stability through strategies like morphology control,surface reconstruction,oxygen vacancy engineering,element doping,metal-assisted catalyst loading,etc.Finally,the paper outlines the challenges and future research directions in the realm of electrocatalytic nitrate reduction for ammonia synthesis.