摘要
采用乙二醇为还原剂的液相还原法和后续热处理途径制备了Pt/Ir原子比1∶1的Pt-Ir合金催化剂,利用X射线衍射(XRD)、透射电子显微镜(TEM)、电感耦合等离子体质谱(ICP)、X射线光电子能谱(XPS)等方法对合金催化剂的形貌和结构进行了表征,并采用循环伏安法(CV)、线性电势扫描(LSV)等电化学方法评价了它们的电催化活性和稳定性。结果表明,经过400℃热处理的Pt-Ir/CNC-400催化剂表现出了高于商业JM催化剂的电催化性能和稳定性。其原因主要在于,Pt-Ir纳米颗粒的合金化作用使颗粒表面的电子结构和组成发生了变化,更有利于提高催化剂的催化活性。
Low durability is the major challenge hindering the large-scale implementation of proton exchange membrane fuel cell （PEMFC） technology. To improve the electrochemical activity and durability of conventional Pt catalyst used in PEMFCs, Pt-Ir alloy catalysts supported on homemade carbon canocages （CNCs） are prepared by a liquid phase reduction method followed by heat treatment at different temperatures. Results from cyclic voltammetry （CV） and linear sweep voltammetry （LSV） show that the Pt-Ir alloy catalyst with Pt/Ir atomic ratio of 1 ： 1 after heat treatment at 400 ℃has a better activity and stability than commercial JM catalyst （Johnson Mattey Co）. It is found that the use of Ir as the alloying element is critical for the observed improvement. Such a Pt-Ir alloy catalyst provides a new replacement for the conventional Pt catalyst with not only a drastic improvement in durability but a reduction in Pt usage by 50 % as well.
