Fe(Pt,Ru)B非晶带材脱合金制备纳米多孔PtRuFe及其甲醇电催化性能  

Fabrication of Nanoporous PtRuFe by Dealloying Amorphous Fe(Pt,Ru)B Ribbons and Their Methanol Electrocatalytic Properties

作　　者：徐秀月 李艳辉[1] 张伟[1] XU Xiuyue;LI Yanhui;ZHANG Wei(Key Laboratory of Materials Modification by Laser,Ion and Electron Beams(Ministry of Education),School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学材料科学与工程学院三束材料改性教育部重点实验室,大连116024

出　　处：《金属学报》2020年第10期1393-1400,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.51771039和51171034。

摘　　要：以Fe65Pt10-xRuxB25(x=0、2、4,原子分数,%)急冷合金带材为前驱体,在0.1 mol/L H2SO4溶液中进行恒电位脱合金化,制备纳米多孔合金,并对合金的相组成和孔结构进行表征,对其甲醇电催化性能进行评价。结果表明,所有急冷合金带材均具有非晶结构,脱合金后可形成由单一fcc结构(Pt,Ru)Fe相组成的纳米多孔合金。当x=0、2时,制备的合金具有均匀双连通纳米多孔结构,平均孔径和韧带尺寸分别为6~7和7~8 nm;x=4时,纳米多孔合金表面有裂纹产生。随x由0增至4,纳米多孔合金在0.5 mol/L H2SO4+1.0 mol/L CH3OH混合溶液中的正扫氧化峰电位依次向负电位方向移动,正扫氧化峰电流密度(jf)先增加后降低,而正扫、反扫氧化峰电流密度的比值(jf/jb)逐渐增加。x=2时,纳米多孔合金的jf和jf/jb分别为0.87 mA/cm2和4.6,分别是x=0时纳米多孔合金的1.7和2.7倍,表明其具有比PtFe合金更高的甲醇电催化活性和抗CO中毒能力。PtRuFe三元纳米多孔合金催化性能的改善源于Pt/Ru双功能机制和加入Ru引起的对CO氧化物种吸附能的减弱。此外,纳米多孔PtRuFe合金还具有铁磁性,便于分离和回收。The growing technological demand for high-efficiency direct methanol fuel cells (DMFCs)drives the exploration of catalysts with improved catalytic performance.Conventional pure Pt with good catalytic activity for methanol oxidation reaction (MOR) have been applied in the DMFCs for several decades,while their CO tolerance still needs to be further enhanced.Formation of nanoporous structure with a high specific surface area is an effective way to increase the catalytic efficiency by providing more active sites.Alloying suitable Fe and Ru into Pt is promising for the improvements of both catalytic activity and anti-CO poisoning.In this work,the nanoporous alloys have been fabricated by dealloying Fe65Pt10-xRuxB25(x=0,2,4,atomic fraction,%) melt-spun alloy ribbons in 0.1 mol/L H2SO4 solution,and the phase structures,morphologies,chemical compositions,and magnetic properties of the melt-spun ribbons and nanoporous alloys were characterized by XRD,TEM,SEM,EDS,XPS and VSM,respectively.The electrocatalytic properties for MOR of the nanoporous alloys were examined by cycle voltammetry in 0.5 mol/L H2SO4+1.0 mol/L CH3OH solution.The results reveal that all melt-spun ribbons are fully amorphous,and nanoporous (Pt,Ru)Fe with a single-fcc phase can be obtained after dealloying.The nanoporous (Pt,Ru)Fe dealloyed from x=0 and 2 precursors possess a similar fine bicontinuous ligament/channel structure with average pore diameter and ligament size of 6~7 and 7~8 nm,respectively.Cracks can be found on the surficial nanoporous architecture for the nanoporous PtRuFe obtained from the x=4 alloy.With enriching of Ru,the oxidation peak potential of the nanoporous alloys exhibits a negative shift,and the ratio (jf/jb) of the peak current density in the forward scan (jf) to that in the backward scan (jb) increases gradually.The jfand jf/jbfor the nanoporous PtRuFe dealloyed from the x=2 alloy is 0.87 m A/cm2 and 4.6,which are 1.7 and 2.7 times of those for the nanoporous PtFe,respectively,indicating the superior electrocatalytic activity

关 键 词：PtRuFe合金 纳米多孔金属 非晶合金 脱合金化 电催化性能 

分 类 号：TG146[一般工业技术—材料科学与工程]