铜硫比对CuS_(x)催化剂CO_(2)电催化还原性能的影响  

Influence of copper-sulfur ratio on the electrochemical performance of CuS_(x)catalysts for CO_(2)reduction

作　　者：高宇璇 郭本帅 罗阳娜 郭亚飞 赵传文 GAO Yuxuan;GUO Benshuai;LUO Yangna;GUO Yafei;ZHAO Chuanwen(School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210023,Jiangsu,China;Sinopec Nanjing Research Institute of Chemical Industry Co.,Ltd.,Nanjing 210048,Jiangsu,China)

机构地区：[1]南京师范大学能源与机械工程学院,江苏南京210023 [2]中石化南京化工研究院有限公司,江苏南京210048

出　　处：《精细化工》2024年第11期2479-2485,2492,共8页Fine Chemicals

基　　金：国家自然科学基金项目(51806108,52276120);江苏省高等学校自然科学基金项目(23KJB470028)。

摘　　要：采用水热合成法制备了CuS_(x)催化剂,通过改变前驱体铜硫比〔n(Cu)∶n(S)〕,调控催化剂形貌和反应路径。将CuS_(x)催化剂用于温和电势下CO_(2)高效电催化还原制CO反应。采用XRD、FESEM和XPS对CuS_(x)催化剂进行了表征,探究了铜硫比对CuS_(x)催化剂电催化CO_(2)还原“构效关系”的影响。结果表明,铜硫比影响CuS晶体成核与生长,进而影响CuS_(x)催化剂的形貌和S空位缺陷。当铜硫比在2∶1~1∶4内变化,CuS_(x)催化剂的形貌由荷花状转化为花球状,S空位含量由20.66%提高至63.37%,CO_(2)电催化还原活性和目标产物CO选择性明显提升。由铜硫比为1∶4制备的CuS_(x)催化剂(CuS-1∶4)在0.1 mol/L的KHCO3电解液中,在–0.51 V vs.RHE(可逆氢电极)的温和电势下,CO选择性达72.67%。CuS-1∶4优异的CO_(2)还原性能归因于催化剂花球状形貌、高比表面积和气体扩散通道提供的不饱和活性位点促进了气体扩散,以及S空位缺陷对电子传递和*COOH中间体在催化剂表面吸附的强化作用。CuS_(x)catalysts were prepared via hydrothermal synthesis,with the morphology and reaction pathway modulated by changing copper sulfur ratio of precursor[n(Cu)∶n(S)],and characterized by XRD,FESEM,and XPS.The CuS_(x)catalysts were then used for catalysis on the efficient electrochemical reduction of CO_(2)to CO at mild potential,and the effect of copper sulfur ratio on their"structure-reactivity"relationships in CO_(2)reduction was analyzed.The results indicated that copper sulfur ratio affected the nucleation and growth of CuS crystals,which in turn exerted impacts on the morphology and sulfur vacancy defects of CuS_(x)catalysts.As the copper sulfur ratio varied from 2∶1 to 1∶4,the morphology of CuS_(x)changed from the lotus shape to ball-flower structure,and the content of sulfur vacancies increased from 20.66%to 63.37%,which resulted in the significant enhancement of CO_(2)reduction activity and CO selectivity.CuS_(x)catalyst(CuS-1∶4)prepared by copper sulfur ratio of 1∶4 showed a CO selectivity of 72.67%in 0.1 mol/L KHCO3 electrolyte at a mild potential of–0.51 V vs.RHE(reversible hydrogen electrode).The excellent CO_(2)reduction performance of CuS-1∶4 was attributed to the fact that its spherical shape,high specific surface area and the unsaturated active sites provided by the gas diffusion channel promoted gas diffusion,as well as the enhancement of the S vacancy defects on the electron transport and*COOH intermediates adsorption on the surface of catalyst.

关 键 词：CuS催化剂 CO_(2)电催化还原 形貌演化 硫空位缺陷 催化技术 

分 类 号：X701[环境科学与工程—环境工程] TB34[一般工业技术—材料科学与工程]