Pd-Au/MXene(Ti_(3)C_(2))纳米复合材料高效能电催化氧化乙醇

The high electrocatalytic performance of Pd-Au/MXene(Ti_(3)C_(2)) nanocomposite for the oxidation of ethanol

设计高性能、低成本的小分子醇类电化学氧化催化剂是直接燃料电池实际应用的一大挑战。利用抗坏血酸(VC)作为还原剂,有效还原钯、金前驱体盐,并与二维(2D)层状结构MXene(Ti_(3)C_(2))有效复合,制得Pd-Au/MXene纳米复合材料,并深入研究该材料在碱性条件下对于乙醇氧化反应的电化学催化性能。通过电子扫描电镜(SEM)、电子透射电镜(TEM)、X射线衍射(XRD)、光电子能谱(XPS)等技术对所得材料的结构及组成进行表征。通过循环伏安法(CV)、交流阻抗法(EIS)和计时电流法(I-t)对所得复合材料对于乙醇的电化学氧化催化性能进行了系统研究。结果表明,当n(PdCl_(4)^(2-))/n(AuCl_(4)^(-))=0.5/1.5时,所得复合材料表现出最优的电催化活性和最高的稳定性,远高于商业钯碳催化剂。

The design of high performance and low cost electrochemical catalysts for small-molecular alcohol oxidations is still a major challenge for the practical application of direct fuel cells.In this study,ascorbic acid(VC)was used as a reducing agent to effectively reduce palladium/gold precursor salts in the presence of two-dimensional(2D)layered structure MXene(Ti_(3)C_(2))nanosheets.As a result,Pd-Au alloy nanoparticles were obtained and effectively compounded with MXene(Ti_(3)C_(2))to form Pd-Au/MXene nanocomposite.The electrochemical catalytic performance of the Pd-Au/MXene nanocomposite for ethanol oxidation in alkaline medium was systematically studied.Their structure and morphology were characterized by electron scanning electron microscopy(SEM),electron transmission electron microscopy(TEM),X-ray diffraction(XRD)and photoelectron spectroscopy(XPS).The electrocatalytic properties of the materials towards ethanol oxidation were studied systematically by cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and chronocurrent(I-t).The results showed that when n(PdCl_(4)^(2-))/n(AuCl_(4)^(-))=0.5/1.5,the obtained nanocomposite performed optimal electrocatalytic activity and the highest stability,which was higher than that of the commercial palladium carbon catalyst.