文献类型：期刊文献

英文题名：High-Performance PdNi Nanoalloy Catalyst in Situ Structured on Ni Foam for Catalytic Deoxygenation of Coalbed Methane: Experimental and DFT Studies

作者：Zhang, Qiaofei[1];Wu, Xin-Ping[2,3];Li, Yakun[1];Chai, Ruijuan[1];Zhao, Guofeng[1];Wang, Chunzheng[1];Gong, Xue-Qing[2,3];Liu, Ye[1];Lu, Yong[1]

机构：[1]East China Normal Univ, Sch Chem & Mol Engn, Shanghai Key Lab Green Chem & Chem Proc, Shanghai 200062, Peoples R China;[2]East China Univ Sci & Technol, Ctr Computat Chem, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2016

卷号：6

期号：9

起止页码：6236

外文期刊名：ACS CATALYSIS

收录：;EI(收录号：20163602780131);WOS:【SCI-EXPANDED(收录号:WOS:000382714000069)】；

基金：This work was financially supported by the "973 program" (2011CB201403) from the MOST of China and the NSF of China (21473057, 21273075, 21322307, U1462129).

语种：英文

外文关键词：structured catalyst; nanoalloy catalysis; foam; coalbed methane; catalytic combustion; reaction kinetics; DFT calculations

摘要：A Ni-foam-structured PdNi nanoalloy catalyst engineered from nano- to macro-scales has been successfully fabricated for the catalytic deoxygenation of coalbed methane (CBM). The catalyst was obtainable by embedment of Pd nanoparticles onto Ni-foam substrate via a galvanic exchange reaction method and subsequent in situ activation in the reaction, which was active at low temperature, selective (no CO formation), and oscillation free in this CH4-rich catalytic combustion process. Special Pd@NiO (Pd nanoparticles partially wrapped by tiny NiO fragments) ensembles were formed in the galvanic deposition stage and could merely be transformed into PdNi nanoalloys in the real reaction stream at elevated temperatures (e.g., 450 degrees C or higher). Density functional theory (DFT) calculations were carried out to reveal the role of Ni decoration at Pd in PdNi nanoalloy catalyst for the CBM deoxygenation. By nature, the Pd Ni alloying modified the electronic structure of surface Pd and led to a decrease in the 0 adsorption energy, which can be taken as the activity descriptor for the CBM deoxygenation. A reaction kinetic study indicated that the Ni decoration at Pd by Pd Ni alloying lowered the apparent activation energy in comparison to the pristine Pd catalyst, while leading to an increase of the reaction order of O-2 from 0.6 at Pd catalyst to 0.3. The foam-structured PdNi nanoalloy catalyst thus offered enhanced low-temperature activity and the elimination of oscillating phenomena as the result of a transient balance obtained between the cycles of O-2 adsorption/activation and CH4 oxidation.