Pd-Sn-Co纳米粒子修饰还原氧化石墨烯/CuBi2O4复合材料的制备及电催化性能

Preparation and electrocatalytic properties of Pd-Sn-Co nanoparticles modified reduced graphene oxide/CuBi2O4 composites

采用水热-浸渍还原法将Pd-Sn-Co纳米粒子固载到氧化石墨烯(GO)/CuBi2O4载体上,成功获得PdSn-Co@还原氧化石墨烯(rGO)/CuBi2O4复合催化剂,并用于碱性介质中乙二醇的电催化氧化。通过比较单金属Pd、双金属Pd-Co、Pd-Sn及三金属Pd-Sn-Co@rGO/CuBi2O4四种负载型催化剂的电催化性能发现,三金属Pd-Sn-Co@rGO/CuBi2O4展现出最高的电催化活性和抗毒能力,其正向峰电流密度达到186.54 mA·cm^-2,是商用Pd/C (29.57 mA·cm^-2)的6.3倍。这种优良的电氧化性能归功于载体GO/CuBi2O4独特的三维结构为负载金属提供了充足的界面和活性位点及良好分散性的Pd-Sn-Co三金属纳米粒子之间强烈的协同作用,此外,将GO引入到CuBi2O4中有利于多金属纳米粒子的负载并吸附更多的含氧物种,提供优良的电子转移并增大与乙二醇分子的接触面积。这种新型复合材料的制备为发展高效Pd基电催化氧化直接醇类燃料电池提供了新途径,具有较好的理论和应用价值。

Trimetallic Pd-Sn-Co nanoparticles(NPs)were successfully fixed on the support graphene oxide(GO)/CuBi2O4 via facile hydrothermal and impregnation-reduction methods.The Pd-Sn-Co@reduced graphene oxide(rGO)/CuBi2O4 catalysts obtained were employed to the electrocatalytic oxidation of ethylene glycol(EG)in an alkaline medium.Compared with the monometallic Pd,bimetallic Pd-Co,Pd-Sn@rGO/CuBi2O4 electrocatalysts,the trimetallic Pd-Sn-Co@rGO/CuBi2O4 exhibits the highest electrocatalytic activity and tolerance of poison species,the forward peak current density as high as 186.54 mA·cm^−2,is about 6.3 times higher than that of commercial Pd/C(29.57 mA·cm^−2).The outstanding electrooxidation performance of Pd-Sn-Co@rGO/CuBi2O4 composites is attributed to the unique 3D structures of support GO/CuBi2O4 which provide plenty of interfaces and achievable reaction active sites for the loading metals,as well as the strong synergistic effects of the well-dispersed Pd-Sn-Co NPs.Besides,the introduction of GO in CuBi2O4 matrix conduces to the loading of multi-metal NPs resulting in more adsorption of oxygenated species,and provides superior electron transfer and improves contact surface area with EG molecules.The study on the new composites offers a conception and applicable way to develop the advanced Pdbased electrocatalysts for high performance direct alcohol fuel cells.