还原温度对石墨烯负载Pd颗粒的结构与电催化性能的影响  

Impact of Reduction Temperature on the Structure and Electrocatalytic Properties of Graphene Supported Pd Nanoparticles

作　　者：王会权 陈惠[1,2] 王后 巫静 刘洪波[1,2] WANG Huiquan;CHEN Hui;WANG Hou;WU Jing;LIU Hongbo(College of Material Science and Engineering, Hunan University, Changsha 410082;Advanced Carbon Materials Research Institute in Hunan Province, Changsha 410082)

机构地区：[1]湖南大学材料科学与工程学院,长沙410082 [2]湖南省先进炭材料研究所,长沙410082

出　　处：《材料导报》2019年第22期3695-3700,共6页Materials Reports

基　　金：国家重点研发计划(2017YFB0310905);国家自然科学基金(51172083);湖南省自然科学基金(2017JJ2027)~~

摘　　要：Pd催化剂对甲酸氧化反应具有出色的电催化性能,适宜的载体有助于改善Pd颗粒的稳定性和分散性,从而使其催化性能得以有效发挥。鉴于此,以硼氢化钠为还原剂,采用化学还原法在不同还原温度(0 ℃、25 ℃和50 ℃)下制备了石墨烯负载Pd颗粒催化剂(Pd/RGO)。采用XRD、Raman、XPS、TGA、TEM和BET等测试方法对该催化剂材料的微观形貌和结构进行了表征,利用循环伏安法和计时电流法测试了催化剂对甲酸氧化反应的电催化性能,着重分析了制备过程中还原温度对催化剂材料结构与电催化性能的影响。结果表明,当还原温度为0 ℃时,Pd/RGO的比表面积最大,达到261 m 2·g^-1 ,Pd颗粒粒径最小,约为4.16 nm;并且Pd/RGO具有最大的电化学活性面积(3.02 cm^2),其氧化峰电流密度最高可达 1 820 mA·mg^-1 Pd。Pd catalyst exhibits exceptional electrocatalytic performance in formic acid oxidation, and suitable supports contribute to the stability and dispersion of Pd particles, which enables Pd particles to give full play of the catalytic performance. Accordingly, we synthesized reduced graphene oxide supported Pd nanoparticles (Pd/RGO) as electrocatalysts for direct formic acid fuel cell by chemical reduction in three different reduction temperatures (0 ℃, 25 ℃ and 50 ℃) with sodium borohydride as reducer. XRD, Raman, XPS, TGA, TEM and BET were employed to characterize the surface morphology and structure of Pd/RGO samples. The electrocatalytic properties of the Pd/RGO electrocatalysts for formic acid oxidation were measured by cyclic voltammetry and chronoamperometry. Emphasis was put on analyzing the impact of reduction temperature on the structure and electrocatalytic performance of the Pd/RGO electrocatalysts. The results indicate that Pd/RGO catalysts prepared under the reduction temperature of 0 ℃ show the largest specific surface area (261 m 2·g -1 ), with well dispersed Pd nanoparticles and the smallest Pd particle size of 4.16 nm on average;meanwhile this Pd/RGO presents the largest electrochemically active surface area (3.02 cm 2) and the highest peak current density (1 820 mA·mg -1 Pd) towards formic acid electrooxidation.

关 键 词：石墨烯 钯 电催化 直接甲酸燃料电池 化学还原 

分 类 号：TB321[一般工业技术—材料科学与工程]