摘要
通过简单的浸渍-还原并随后在酸性溶液中处理制备了Pt-Cu双金属催化剂.利用电感耦合等离子体发射光谱、X射线衍射和X射线光电子能谱对不同处理条件下的Pt-Cu纳米粒子的结构和组成进行了表征.研究发现,Pt-Cu催化剂在高温H2中还原形成了PtCu3合金结构,酸洗处理后形成了包含Pt-骨架(Pt-skeleton)的表面结构和PtCu3合金核的纳米粒子.而Pt-骨架结构又可通过在H2中退火转变为规整的Pt-表层(Pt-skin)结构.Pt-表层表面修饰Fe氧化物后在CO选择氧化反应中表现出较好的催化性能.通过此方法制备的三金属Pt-Cu-Fe催化剂可达到与Pt-Fe相近的高活性,并且催化剂中Pt的用量大大降低.
Pt-Cu/carbon black catalysts were prepared by an impregnation-reduction method followed by acid leaching.The structure and composition of Pt-Cu nanoparticles treated under different conditions were investigated by inductively coupled plasma atomic emission spectrometry,X-ray diffraction,and X-ray photoelectron spectroscopy.PtCu3 alloy formed upon annealing Pt-Cu/carbon black cata- lysts in H2.Acid leaching produced Pt-Cu nanoparticles consisting of Pt-skeleton surface structure and PtCu3 alloy core. The Pt-skeleton could be transformed to well-defined Pt-skin structure through further annealing the leached Pt-Cu nanoparticles in H2.Decorating the Pt-skin surfaces with Fe oxide nanopatches resulted in enhanced reactivity in the preferential oxidation of CO in excess H2.The tri-component Pt-Cu-Fe catalysts exhibited comparable activity to the bi-component Pt-Fe catalysts but used much less Pt.
出处
《催化学报》
CSCD
北大核心
2013年第11期2029-2035,共7页
基金
supported by the National Natural Science Foundation of China (21222305, 11079005, 20923001)
the National Basic Research Program of China (973 Program, 2013CB834603, 2011CBA00503, 2013CB933100)~~
