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双金属催化材料的催化性质可以通过在原子水平下控制材料的表面结构和组成进行有效调节.本文发展了一种普适性的方法合成具有高度分散性、洁净表面和可调的表面结构和组成的Pt_xNi_(1-x)八面体纳米粒子.研究发现在反应过程中,通过增加Ni前驱体的含量,合成的Pt_xNi_(1-x)八面体纳米粒子的(111)晶面的凹陷程度逐渐加大.我们系统研究了Pt_xNi_(1-x)八面体纳米粒子的表面结构或组成与其氧还原电催化活性之间的相互关系.电化学研究结果表明所有的Pt_xNi_(1-x)八面体纳米粒子均表现出比标准商业Pt/C催化剂更高的氧还原活性.更重要的是,我们发现Pt_xNi_(1-x)八面体纳米粒子的表面结构和组成对其氧还原电催化活性具有很大的影响.研究发现,具有轻微(111)晶面凹陷程度的Pt_1Ni_1八面体纳米粒子显示出最高的氧还原电催化活性.在0.9 V(相对于标准氢电极)电势条件下,Pt_1Ni_1八面体纳米粒子的氧还原质量活性和面积活性分别为标准商业Pt/C催化剂的7.0和7.5倍.该研究不仅提供了一种普适性的方法合成具有高度分散性、洁净表面和可调的表面结构和组成的Pt_xNi_(1-x)八面体纳米粒子,同时可为理解催化材料的结构-性质相互关系规律提供指导.
The catalytic properties of bimetallic catalytic materials can be effectively tuned by controlling the surface structure and composition of the material at the atomic level.This paper develops a universal method for the synthesis of highly dispersive, clean surfaces and tunable surface structures and compositions Of Pt_xNi_ (1-x) octahedron nanoparticles were studied.The results show that the dent of (111) crystal plane of Pt_xNi_ (1-x) octahedron nanoparticles is gradually increased by increasing the content of Ni precursor during the reaction We systematically studied the relationship between the surface structure and composition of Pt_xNi_ (1-x) octahedral nanoparticles and their oxygen reduction electrocatalytic activity.The electrochemical results show that all the Pt_xNi_ (1-x) octahedron nanoparticles All showed higher oxygen reduction activity than the standard commercial Pt / C catalysts.More importantly, we found that the surface structure and composition of Pt_xNi_ (1-x) octahedral nanoparticles have a great influence on their oxygen reduction electrocatalytic activity It was found that Pt_1Ni_1 octahedral nanoparticles with a slight degree of depression of the (111) crystal plane showed the highest electrocatalytic activity for oxygen reduction.At 0.9 V (vs. standard hydrogen electrode), Pt_1Ni O1 octahedron nanoparticles have an oxygen reduction mass activity and an area activity of 7.0 and 7.5 times that of a standard commercial Pt / C catalyst, respectively. This study not only provided a universal method for the synthesis of highly dispersible, clean surfaces and tunable Pt-xNi_ (1-x) octahedron nanoparticles and provide guidance for understanding the structure-property relationship of the catalytic materials.