具有可控晶面的Co_(3)O_(4)催化剂用于高性能电化学析氯反应  

Tailoring crystal planes in Co_(3)O_(4) for enhanced chlorine evolution reaction electrocatalysis

作　　者：茆志贤 陈珊 吉加鹏 尹华杰 Zhixian Mao;Shan Chen;Jiapeng Ji;Huajie Yin(University of Science and Technology of China,Hefei 230026,China;Key Laboratory of Materials Physics,Centre for Environmental and Energy Nanomaterials,Anhui Key Laboratory of Nanomaterials and Nanotechnology,Institute of Solid State Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;Institutes of Physical Science and Information Technology,Anhui University,Hefei 230039,China;Institute of Technology for Carbon Neutrality,Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,China)

机构地区：[1]中国科学技术大学,合肥230026 [2]中国科学院合肥物质科学研究院,固体物理研究所,安徽省纳米材料与技术重点实验室,环境与能源纳米材料研究中心,材料物理重点实验室,合肥230031 [3]安徽大学,物质科学与信息技术研究院,合肥230039 [4]中国科学院深圳先进技术研究院,碳中和技术研究所,广州518055

出　　处：《科学通报》2024年第25期3748-3756,共9页Chinese Science Bulletin

基　　金：国家自然科学基金(52102325)资助。

摘　　要：电化学析氯反应(CER)是氯碱工业电解池和海水电解池的重要阳极反应,具有优异活性与稳定性的尺寸稳定阳极(DSA)是目前主要使用的CER阳极材料.然而DSA电极面临着Ru和Ir等贵金属稀缺性和昂贵价格等问题,故发展非贵金属基高性能CER电催化剂具重要意义.但当前针对非贵金属基CER催化剂相关研究仍然较少,主要挑战在于难以兼顾CER高活性和酸性电解质高氧化电位下的稳定性.本文提出对尖晶石结构的Co_(3)O_(4)进行晶面调控来提高其CER活性和稳定性的策略.通过诱导{112}晶面的形成以取代较为稳定{111}晶面,从而暴露出更高密度的八面体位点(Cooct).在4 mol L^(-1)NaCl(pH 2)作为电解质的条件下,暴露{112}晶面的Co_(3)O_(4)在电流密度为100 mA cm^(-2)时的CER过电位仅为170 m V,远低于{111}晶面Co_(3)O_(4)的330 mV,并优于商业RuO_(2)的320 mV.此外,其具有接近100%的法拉第效率以及优异的稳定性(在10 mA cm^(-2)持续17 h的恒电流测试后,溶解钴浓度仅为8 ppb(1 ppb=1μg L^(-1))).密度泛函理论(DFT)计算也表明{112}面具有对Cl^(-)更优的吸附能.该研究为如何利用晶面合理设计高效的Co基非贵金属CER催化剂提供新的途径.As a crucial chemical, chlorine(Cl_(2)) boasts an annual output exceeding 30 million tons in China, finding extensive application in the production of plastic monomers such as polyvinyl chloride as well as in water treatment, bleaching, and fine chemical synthesis. The primary method for producing chlorine involves the electrolysis of saturated brine using ion exchange membrane electrolyzers within the chlor-alkali industry, where electrochemical chlorine evolution(CER) occurs at the anode. The dimensionally stable anode(DSA), composed of noble metal oxides, including Ru and Ir, has been the predominant commercial CER electrode since its development in the mid-1960s owing to its outstanding CER activity/selectivity and high stability in acidic electrolytes. Nevertheless, the scarcity and high cost of precious metals such as Ru and Ir necessitate the development of high-performance, non-precious metal-based CER electrocatalysts. Despite this,research on non-noble metal-based CER catalysts remains limited, primarily because balancing the high activity of CER with the stability required for the high oxidation potential of acidic electrolytes proves challenging. Recent advancements have shown that cobalt-based oxides exhibit exceptional acidic oxygen evolution reaction(OER) activity at the anode during water electrolysis in proton exchange membranes. Given that chlorine and oxygen evolution reactions partially share an active site—specifically, the metal–oxygen bond serves as an adsorption intermediate for both reactions—it is theorized that catalysts effective for oxygen evolution may also facilitate chlorine evolution. Consequently, we postulate that the Co-based material system can serve as an effective CER catalyst. In this study, we use a strategy to enhance the CER activity and stability of spinel-structured Co_(3)O_(4)by manipulating its crystal planes. In particular, exposure of the{112} crystal planes is enhanced through low-temperature induction of α-Co(OH)_(2)monocrystalline nanosheets. Based on XPS

关 键 词：析氯反应 海水电解 四氧化三钴 晶面效应 非贵金属 

分 类 号：O643.36[理学—物理化学] TQ124.41[理学—化学]