Recent Advances in Transition Metal-Based Catalysts for Electrocatalytic Nitrate Reduction Reaction

过渡金属基催化剂电催化硝酸盐还原反应研究进展

The accumulation of excessive nitrate in the atmosphere not only jeopardizes human health but also disrupts the balance of the nitrogen cycle in the ecosystem.Among various nitrate removal technologies,electrocatalytic nitrate reduction reaction(eNO_(3)RR)has been widely studied for its advantages of being eco-friendly,easy to operate,and controllable under environmental conditions with renewable energy as the driving force.Transition metal-based catalysts(TMCs)have been widely used in electrocatalysis due to their abundant reserves,low costs,easy-to-regulate electronic structure and considerable electrochemical activity.In addition,TMCs have been extensively studied in terms of the kinetics of the nitrate reduction reaction,the moderate adsorption energy of nitrogen-containing species and the active hydrogen supply capacity.Based on this,this review firstly discusses the mechanism as well as analyzes the two main reduction products(N_(2)and NH_(3))of eNO_(3)RR,and reveals the basic guidelines for the design of efficient nitrate catalysts from the perspective of the reaction mechanism.Secondly,this review mainly focuses on the recent advances in the direction of eNO_(3RR)with four types of TMCs,Fe,Co,Ni and Cu,and unveils the interfacial modulation strategies of Fe,Co,Ni and Cu catalysts for the activity,reaction pathway and stability.Finally,reasonable suggestions and opportunities are proposed for the challenges and future development of eNO_(3)RR.This review provides far-reaching implications for exploring cost-effective TMCs to replace high-cost noble metal catalysts(NMCs)for eNO_(3)RR.

大气环境中过量硝酸盐的积累不仅会危害人体健康,还会破坏生态系统的氮循环平衡。在众多硝酸盐去除技术中,电催化硝酸盐还原技术因其环保、操作简便、在可再生能源驱动环境条件下可控等优点而被广泛研究。过渡金属基催化剂由于其储量丰富、成本低、电子结构易调控及电化学活性可观,在电催化领域被广泛应用。此外,过渡金属基催化剂在硝酸盐还原反应动力学、含氮物种适中的吸附能及活性氢供应能力等方面得到广泛研究。基于此,该综述首先讨论了电催化硝酸盐还原机理,分析了两种主要还原产物(N_(2)和NH_(3)),并从反应机理的角度分析了设计高效硝酸盐催化剂的基本准则。其次,总结了过渡金属Fe、Co、Ni及Cu四类催化剂在电催化硝酸盐还原方向的研究进展,并提出了其反应活性、反应路径及稳定性的界面调控策略。最后,对电催化硝酸盐还原存在的问题给出了建议,展望了其未来发展机遇。该综述为探索经济有效的过渡金属基催化剂替代高成本贵金属催化剂用于电催化硝酸盐还原反应提供了启示。