The origin of active sites for direct synthesis of H2O2 on Pd/TiO2 catalysts: Interfaces of Pd and PdO domains

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	The origin of active sites for direct synthesis of H2O2 on Pd/TiO2 catalysts: Interfaces of Pd and PdO domains
	Ouyang, L; Tian, PF; Da, GJ; Xu, XC; Ao, C; Chen, TY; Si, R; Xu, J; Han, YF
刊名	JOURNAL OF CATALYSIS
	2015
卷号	321 页码:70—80
关键词	HYDROGEN-PEROXIDE SYNTHESIS GOLD-PALLADIUM CATALYSTS NEAR-ATMOSPHERIC PRESSURES PD/SIO2 CATALYST DIRECT OXIDATION BIMETALLIC CATALYSTS H2SO4/ETHANOL SYSTEM COLLOIDAL PALLADIUM AMBIENT CONDITIONS MOLECULAR-OXYGEN
英文摘要	Direct synthesis of H2O2 from H-2 and O-2 on Pd/TiO2 catalysts has been systematically studied to gain understanding of the origin of active sites. For the first time, the structure of Pd ensembles has been demonstrated to be finely tuned by the variation of Pd loading without change in the particle size. The structure of Pd/TiO2 catalysts has been thoroughly characterized using multiple techniques such as HRTEM, XRD, in situ DRIFTS, XPS, XANES, and EXAFS. With the variation of Pd loading in the range 1.0-5.0 wt%, the size (ca. 2.4 nm in diameter) and crystallinity of Pd particles have shown no discernible differences, while the surface configuration of Pd atoms changed significantly. Performance (a selectivity of 61% to H2O2 and a rate in TOF of 630 h(-1)) was optimal for a catalyst of 1.0 wt% Pd at 283 K and 1 atm using a semibatch reactor. We demonstrate that part of the surface Pd atoms can be oxidized (47.6% for 1.0 wt% Pd and 35.2% for 5.0 wt% Pd) by the adsorbed oxygen with the assistance of TiO2 even at 283 K, and form Pd-PdO ensembles. The electronic structure of the surface Pd atoms has proved to change dynamically in different atmospheres. We assume that H2O2 synthesis occurs at the interfaces of the Pd and PdO domains. In addition, the deep insight into the origin of active sites from this paper, as a case study, reminds us that the structure of active sites of support catalysts can be potentially tuned by varying the metal loading. (c) 2014 Elsevier Inc. All rights reserved.
收录类别	SCI
语种	英语
公开日期	2015-12-24
内容类型	期刊论文
源URL	[http://ir.sinap.ac.cn/handle/331007/24598]
专题	上海应用物理研究所_中科院上海应用物理研究所2011-2017年
推荐引用方式 GB/T 7714	Ouyang, L,Tian, PF,Da, GJ,et al. The origin of active sites for direct synthesis of H2O2 on Pd/TiO2 catalysts: Interfaces of Pd and PdO domains[J]. JOURNAL OF CATALYSIS,2015,321:70—80.
APA	Ouyang, L.,Tian, PF.,Da, GJ.,Xu, XC.,Ao, C.,...&Han, YF.(2015).The origin of active sites for direct synthesis of H2O2 on Pd/TiO2 catalysts: Interfaces of Pd and PdO domains.JOURNAL OF CATALYSIS,321,70—80.
MLA	Ouyang, L,et al."The origin of active sites for direct synthesis of H2O2 on Pd/TiO2 catalysts: Interfaces of Pd and PdO domains".JOURNAL OF CATALYSIS 321(2015):70—80.