Dynamic tracking of exsolved PdPt alloy/perovskite catalyst for efficient lean methane oxidation  

作　　者：Yanling Yang Zhenfa Ding Huimin Wang Jianhui Li Yanping Zheng Hongquan Guo Li Zhang Bing Yang Qingqing Gu Haifeng Xiong Yifei Sun 

机构地区：[1]College of Energy,Xiamen University,Xiamen 361005,China [2]School of Environment and Civil Engineering,Dongguan University of Technology,Dongguan 523808,China [3]Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China [4]State Key Laboratory of Physical Chemistry of Solid Surfaces,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China [5]CAS Key Laboratory of Science and Technology on Applied Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China [6]Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM),Xiamen 361102,China

出　　处：《Chinese Chemical Letters》2024年第4期170-175,共6页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos.22272136, 22202041, 22102135, 22202163,22172129);the Fundamental Research Funds for the Central Universities (No.20720220119);Science and Technology Project of Fujian Province (No.2022L3077);the financial support from Guangdong Basic and Applied Basic Research Fund (No.2022A1515110239);the funds from Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM)(No.HRTP-[2022]-3);the Fundamental Research Funds for the Central Universities (No.20720220008)。

摘　　要：Supported Pd based catalysts are considered as the efficient candidates for low-carbon alkane oxidation for their outstanding capability to break C-H bond. Whereas, the irreversible deactivation of Pd based catalysts was still frequently observed. Herein, we reinforced the extruded Pd nanoparticles with quantitive Pt to assemble the evenly distributed Pd Pt nanoalloy onto ferrite perovskite(Pd Pt-LCF) matrix with strengthened robustness of metal/oxide support interface. We further co-achieved the enhanced performance, anti-overoxidation as well as resistance of vapor-poisoning in durability measurement. The operando X-ray photoelectron spectroscopy(O-XPS) combined with various morphology characterizations confirms that the accumulation of surface deep-oxidation species of Pd^(4+) is the culprit for fast activity loss in exsolved Pd system, especially at high temperature of 400 ℃. Conversely, it could be completely suppressed by in-situ alloying Pd with equal amount of Pt, which helps maintain the metastable Pd^(2+)/Pd shell and metallic solid-solution core structure. The density function theory(DFT) calculations further buttress that the dissociation of C–H was facilitated on alloy/perovskite interface which is, on the contrary, resistant toward O–H bond cleavage, as compared to Pd/perovskite. Our work suggests that the modification of exsolved metal/oxide catalytic interface could further enrich the toolkit of heterogeneous catalyst design.

关 键 词：EXSOLUTION PdPt alloy Operando characterization Methane conversion Deep-oxidation 

分 类 号：TQ426[化学工程]