文献类型：期刊文献

英文题名：The origin of palladium particle size effects in the direct synthesis of H2O2: Is smaller better?

作者：Tian, Pengfei[1];Ouyang, Like[1];Xu, Xingyan[1];Ao, Can[1];Xu, Xinchao[1];Si, Rui[2];Shen, Xiangjian[3];Lin, Ming[4];Xu, Jing[1];Han, Yi-Fan[1,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Chinese Acad Sci, Shanghai Inst Appl Phys, Shanghai Synchrotron Radiat Facil, Shanghai 201204, Peoples R China;[3]Zhengzhou Univ, Sch Chem Engn & Energy, Res Ctr Heterogeneous Catalysis & Engn Sci, Zhengzhou 450001, Peoples R China;[4]ASTAR, IMRE, Singapore 138634, Singapore

年份：2017

卷号：349

起止页码：30

外文期刊名：JOURNAL OF CATALYSIS

收录：;EI(收录号：20171303494371);WOS:【SCI-EXPANDED(收录号:WOS:000401217600004)】；

基金：The authors are grateful for support from the National Science Foundation - China (21176071, U1463205, 91534127, and 21506053), the International Cooperation Project of Shanghai Ministry of Science and Technology (14230710700), and the Chinese Education Ministry 111 project (B08021).

语种：英文

外文关键词：Size effects; Subnano clusters; Pd/HAp catalysts; H2O2 synthesis; Structure-performance relationship

摘要：A series of size-controlled Pd/hydroxyapatite (HAp) catalysts ranging from single sites (Pd clusters) to nanoparticles (dpd: similar to 30 nm) was prepared and examined for the H2O2 synthesis directly from H-2 and O-2. A Pd/HAp (dpd: similar to 1.4 nm) showed a high selectivity of 94% toward H2O2 under mild conditions (283 K and atmospheric pressure). The crystal phase, morphology, surface electronic states and coordination number of Pd particles from atomic level to nano scale were characterized in detail using multiple techniques such as X-ray diffraction, scanning transmission electron microscopy, and extended X-ray absorption fine structure. Density functional theory calculations indicated that Pd clusters of subnano size have the most effective active sites for the selective activation of oxygen hydrogenation, thus resulting in high catalytic efficiency for H2O2 synthesis. This work elucidates why those smaller Pd particles in a proper size range show the best catalytic performance for H2O2 synthesis. (C) 2016 Elsevier Inc. All rights reserved.