Improvement of electrocatalytic alcohol oxidation by tuning the phase structure of atomically ordered intermetallic Pd-Sn nanowire networks  

原子有序钯-锡金属间化合物纳米线网的相结构调控提高乙醇电催化氧化

作　　者：Zhengshuai Cao Xianzhuo Lao Fahui Gao Min Yang Jing Sun Xuehua Liu Rui Su Jianyu Chen Peizhi Guo 曹政帅;劳显焯;高法辉;杨敏;孙静;刘雪华;苏瑞;陈建宇;郭培志(Institute of Materials for Energy and Environment,College of Materials Science and Engineering,Qingdao University,Qingdao 266071,China)

机构地区：[1]Institute of Materials for Energy and Environment,College of Materials Science and Engineering,Qingdao University,Qingdao 266071,China

出　　处：《Science China Materials》2022年第10期2694-2703,共10页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(22172084 and 21773133);the World-Class Discipline Program of Shandong Province,China。

摘　　要：Atomically ordered intermetallic compounds(OICs)have aroused remarkable interests for wide applications and are considered as very promising materials for electrocatalysis owing to the strict stoichiometry,well-defined atom binding environment,and the specific crystalline phase.However,the tunable synthesis of the intermetallics remains a giant challenge.Herein,this study reports the preparation of the Pd-Sn OICs composed of an interconnected nanowire network structure with adjustable molar ratios of elements Pd and Sn.The co-reduction of Pd(acac)_(2) and SnCl_(2)·2H_(2)O in ethylene glycol(EG)in the presence of sodium hypophosphite(NaH_(2)PO_(2))as the reducing agent affords OICs of three phases:hexagonal Pd_(3)Sn_(2-)P6_(3)/mmc,orthorhombic PdSn-Pnmb,and orthorhombic PdSn_(2)-Aba_(2).Also,the pure phase can convert to two mixed phases(Pd_(3)Sn_(2)/PdSn and PdSn/PdSn_(2))by just altering the feed ratio.It is found that orthorhombic PdSn-Pnmb OIC has a large electrochemically active surface area(ECSA),excellent electrocatalytic performance(4857 mA mg_(Pd)^(−1)),and outstanding stability toward ethanol oxidation reaction(EOR),which could be attributed to its optimal electronic structure.These results demonstrate that the phase engineering of OICs with desired components is an excellent way for catalysts design.原子有序的金属间化合物因其严格的化学计量与原子结合环境及特定的结晶相引起了人们的研究兴趣,并被认为是一类非常有前景的电催化材料.然而,金属间化合物纳米结构的可控合成仍面临挑战.本文研究了晶相可调Pd-Sn金属间化合物纳米线组成的网状结构的制备,即在乙二醇溶液中以次磷酸二氢钠为还原剂将乙酰丙酮钯和二水合氯化亚锡共还原,得到三种金属间化合物纳米线网状结构:六方晶系的Pd_(3)Sn_(2-)P6_(3)/mmc,正交晶系的PdSn-Pnmb和正交晶系的PdSn_(2)-Aba2.改变投料比可实现由单相到混合两相的转换.研究发现,PdSn-Pnmb具有较大的电化学活性比表面积、优异的电催化活性(4857 mA mgPd^(−1))以及对乙醇电氧化反应显著的稳定性,这归因于其最优的电子结构.结果表明,理想组分的金属间化合物的相工程调控是催化剂设计的一种有效途径.

关 键 词：PDSN intermetallic compounds alloy ELECTROCATALYSIS fuel cell 

分 类 号：O643.36[理学—物理化学]