摘要
硝酸盐是地下水中最有害的污染物之一,会严重影响人类健康,亟需发展有效的去除措施.传统的处理方法既耗能又不经济,且去除效果不理想,而氨肥料作为重要的资源,也亟待采取既环保又经济的制备策略.电催化硝酸根还原法(NO3RR)既能去除NO3-污染,实现固氮的同时生成得到高附加值氨(NH3),因而受到了广泛的关注.NO3RR能够获得较高的NH3产率和法拉第效率(FENH3),同时避免竞争性氢析出反应(HER),并且无需克服强的N≡N三键(941kJmol-1).铜(Cu)基材料价格低廉、储量丰富,并且具有优异的催化性能和较弱的HER活性等优势,其在NO3RR中展现出特殊活性,但离实际应用还有一定距离,因此,亟需通过改性策略优化Cu基材料,从而提高催化剂的性能.本文概述了Cu基材料电催化NO3RR转化的最新进展,重点讨论了各种Cu基材料在设计、合成和性能优化方面的研究,如晶面工程、合金与掺杂、异质结构、空位工程和单原子结构等不同的材料设计与调控手段,阐明了使催化剂具有更优越的反应活性、选择性、FENH3和稳定性的设计、合成和调控思路.最后,简要讨论了该领域的发展方向和挑战,并展望了 NO3RR的工业应用发展.
Abstract
Nitrate(NO3-)is one of the most harmful pollutants in natural water systems,which can seriously affect human health.Therefore,it is urgent to develop effective removal measures.Traditional treatment methods are energy consuming and uneconomical,and the removal effect is not ideal.Besides,ammonia(NH3)resource is a crucial resource for synthesizing agricultural fertilizers,chemical compounds,and other nitrogen-rich products,which benefit in balancing the environmental nitrogen cycle.As an important resource,ammonia fertilizer also needs to adopt a preparation strategy that is both environmentally friendly and economical.Electrocatalytic nitrate reduction reaction(NO3RR)is a novel technology that can not only remove NO3-pollution,but also generate high added value NH3,thus attracting widespread attention.The core of NO3RR technology is the catalytic materials,which will to promote the development and application of NO3RR technology by optimizing.By designing materials to improve selectivity and directing the reaction pathway towards ammonia,we can achieve a more economically valuable and effective nitrogen cycle.Cuprum(Cu)based materials are cheap,abundant in reserves,and have advantages such as excellent catalytic performance in NO3RR and weak hydrogen evolution reaction(HER)activity.It can achieve high NH3 yield and Faraday efficiency(FENH3)while avoiding competitive HER.However,there is still a certain distance from practical application.Therefore,it is urgent to optimize Cu-based materials by regulation strategies to improve catalyst performance.Recently,researchers have mainly explored metallic copper,single-atom copper,copper alloy and copper-based composites.However,there is a lack of systematic discussions introducing and summarizing the Cu-based materials for NO3RR,particularly regarding the distinct material systems and the regulatory mechanisms that enhance NO3RR.Therefore,it is crucial to describe the design,synthesis,and regulation strategies for Cu-based catalysts that exhibit improved reactivity,selectivity,faradaic efficiency(FE)towards NH3,and stability.This paper introduces the electrochemical NO3RR through Cu-based materials to generate ammonia and clarifies the reaction mechanism.It compares and summarizes the recent development material of Cu-based for electrochemical NO3RR,focusing on the design,synthesis,and performance optimization of various Cu-based materials,such as crystal surface engineering,alloys and doping,heterostructure,vacancy engineering,and single atomic structure.Firstly,the NO3RR properties of Cu nanoparticles are affected by their morphology and valence state.It is necessary to enhance the activity and performance by constructing different nanostructures,adjusting the exposure ratio of the highly active crystal surface,and increasing the active site.Secondly,alloy engineering and heteroatom doping strategies can achieve better selectivity,activity,and efficiency in NO3RR by introducing second element synergies and regulating electron interactions,which benefit by increasing the specific surface area and exposing more active sites.Thirdly,the Cu base heterogeneous catalysts exhibit a synergistic effect of multiple components and the strong interface effect,which can establish a large number of high-speed electron-transport channels and induce the electron coupling effect synchronously,thus improving the activity by accelerating the electron transfer and optimizing the free energy required by the reaction intermediates.Furthermore,the construction of a vacancy defect structure can increase the unsaturation of the catalyst surface,which is conducive to the adsorption and activation of NO3RR.Appropriate vacancy content is conducive to regulating the adsorption energy of reaction intermediates and improving the selectivity and FENH3.Next,single-atom catalysts(SACs)offer the advantages of both homogeneous and heterogeneous catalysts due to their high atomic utilization efficiency.SACs possess excellent selectivity and electrocatalytic activity.Their fully exposed active sites can enhance the activity of SACs,efficiently anchor and activate NO3-,and inhibit the formation of dinitrogen products.Finally,it briefly discusses the development direction and challenges in this field,and looks forward to the development of industrial applications of NO3RR.
基金项目
国家自然科学基金(22075211)
广西自然科学基金杰出青年基金(2024GXNSFFA010008)
广西研究生教育创新计划(YCBZ2023009)
维普
万方数据