期刊
CATALYSIS TODAY
卷 264, 期 -, 页码 98-108出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.cattod.2015.08.041
关键词
MWW; Porosity; Ti coordination; Propylene epoxidation
资金
- Ministry of Science & Technology, Taiwan [NSC101-2113-M-002-012-MY3, NSC102-2811-M-002-136]
- Natural Science Foundation, China (NSFC) [21306143]
- Scientific Research Foundation for the Returned Overseas Chinese Scholars, Education Ministry, China
Two types of novel catalysts consisting of gold nanoparticles (NPs) supported on the Ti-incorporated MWW structures were compared. One is Ti-YNU-1 with 0.67 nm micropores between expanded 2D-MWW structures, and the other is the titanosilicate pillared MCM-36 (Si/Ti-MCM-36) with 2 nm mesopores. The influences of pore structure and Ti coordination environment on the particle size of anchored Au NPs and their catalytic performances in propylene epoxidation with mixtures of H-2 and O-2 were investigated. The catalyst materials were characterized with Electron Probe Micro Analysis, X-ray diffraction, nitrogen sorption, UV-visible diffuse reflectance spectroscopy, transmission electron microscopy, and X-ray absorption spectroscopy. The coordination environment of Ti(IV) in Ti-YNU-1 is mainly isolated tetrahedral (T-d), while that in Si/Ti-MCM-36 was found to be a mixture of Td and octahedral (O-h). The Au loading was proportional to the amount of Ti incorporated in the porous silica. The particle size of Au NPs in the Si/Ti-MCM-36 support was a little larger than that in the Ti-YNU-1 support, and it is attributed to that the highly isolated Td Ti(IV) in Ti-YNU-1 is favorable for attaining the smaller gold NPs, while the higher loading of Ti in Si/Ti-MCM-36 anchored more Au and resulted in the formation of larger Au particles. On the other hand, the mesopores in Si/Ti-MCM-36 facilitated the diffusion of the produced PO in pore structure, inhibited the further reaction for side product formation, and moderated the deactivation of catalysts. (C) 2015 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据