Pd_(1-x)W_(x)/C催化剂的制备及其催化氧还原性能  

Preparation of Pd_(1-x)W_(x)/C catalysts and its catalytic performances towards oxygen reduction

作　　者：马松艳[1] 赵东江[1] 田喜强[1] 生冬辉 Ma Song-yan;Zhao Dong-jiang;Tian Xi-qiang;Sheng Dong-hui(School of Food and Pharmaceutical Engineering,Suihua University,Heilongjiang Suihua 152061,China)

机构地区：[1]绥化学院食品与制药工程学院,黑龙江绥化152061

出　　处：《炭素技术》2021年第1期37-41,共5页Carbon Techniques

基　　金：黑龙江省自然科学基金联合引导项目(LH2019B034);黑龙江省教育厅基本科研业务费基础研究项目(2016-KYYWF-0923)。

摘　　要：采用乙酰丙酯钯和六羰基钨为前驱体,选择Vulcan XC-72炭黑为载体,在1,6-己二醇介质中利用回流法一步制备了Pd_(1-x)W_(x)/C(x=0、0.1、0.2、0.3)催化剂。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和旋转圆盘电极(RDE)测试技术对催化剂进行表征。结果表明,Pd_(1-x)W_(x)/C样品具有面心立方结构,W原子进入Pd晶格形成Pd-W合金。Pd_(1-x)W_(x)粒子形成的聚集颗粒均匀分布在炭载体上。在氧气饱和电解液中,Pd_(1-x)W_(x)/C具有较好的氧还原催化性能,Pd_(0.8)W_(0.2)/C的催化活性最高,氧还原起始电位为0.88 V(vs.NHE),在1600 r/min和0.40 V电位时极限电流密度是Pd/C的1.4倍。在动力学电位范围内,Pd_(1-x)W_(x)/C催化剂的Tafel斜率和传递系数接近理论值,表明氧还原反应(ORR)由第一个电子转移过程控制。W添加对Pd/C催化剂氧还原催化性能的影响主要归因于W元素进入Pd晶格,改变了Pd周围电子结构。Pd_(1-x)W_(x)/C(x≥0,0.1,0.2,0.3)catalysts were prepared by reflux method using Pd(C_(5)H_(7)O_(2))_(2)and W(CO)_(6)as precursors and Vulcan XC-72 carbon black as carrier in 1,6-hexanediol medium.The catalysts were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM)and rotating disk electrode(RDE)techniques.The results have shown that Pd_(1-x)W_(x)/C samples have face-centered cubic structure and Pd-W alloy is formed by the entry of W atom into Pd lattice.The Pd_(1-x)W_(x)aggregated particles are uniformly distributed on the carbon carrier.In oxygen saturated electrolyte,Pd_(1-x)W_(x)/C catalysts show better catalytic performance for oxygen reduction,and the catalytic activity of Pd_(0.8)W_(0.2)/C with the initial potential of 0.88 V(vs.NHE)is the highest,and the limit current density is 1.4 times higher than that of Pd/C at 1600 r/min and 0.40 V(vs.NHE).In the range of kinetic potential,the Tafel slope and transfer coefficient of Pd_(1-x)W_(x)/C catalysts are close to the theoretical values,indicating that the oxygen reduction reaction(ORR)is controlled by the first electron transfer process.The effect of W addition on the catalytic performance of Pd/C catalyst for the ORR is mainly attributed to the fact that the W element enters the Pd crystal lattice and changes the electronic structure around the Pd.

关 键 词：聚合物电解质膜燃料电池 非铂催化剂 Pd-W合金 氧还原反应 回流法 

分 类 号：TQ426[化学工程] O646[理学—物理化学]