文献类型：期刊文献

中文题名：Au/TS-1 catalyst for propylene epoxidation with H_(2)and O_(2):Effect of surface property and morphology of TS-1 zeolite

作者：Jialun Xu[1];Zhihua Zhang[1];Daiyi Yu[1];Wei Du[1];Nan Song[1];Xuezhi Duan[1];Xinggui Zhou[1]

机构：[1]State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China

年份：2023

卷号：16

期号：5

起止页码：6278

中文期刊名：Nano Research

外文期刊名：纳米研究（英文版）

收录：CSTPCD;;Scopus;CSCD:【CSCD2023_2024】；PubMed;

基金：the funds from the Research Fund for National Key Research and Development Program of China(No.2021YFA1501403);the National Natural Science Foundation of China(Nos.21922803 and 22038003);Shanghai Rising-Star Program(No.17QA1401200);the Innovation Program of the Shanghai Municipal Education Commission(No.17ZR1407300).

语种：英文

中文关键词：propylene epoxidation;titanium silicalite-1(TS-1);surface properties;Ti species;morphological regulation;diffusion

摘要：The catalytic performances over propylene epoxidation with H_(2)and O_(2)(HOPO process)are significantly affected by the properties(e.g.,surface properties,Ti coordination,morphology)of titanosilicate zeolite.Introducing urea into zeolite synthesis is a simple and convenient method to modify these properties of titanosilicate zeolite.Uncalcined pore-blocked titanium silicalite-1(TS-1,i.e.,TS-1-B)with the lower urea dosage possesses more defective structure and unsaturated coordinated Ti sites verified by 29Si nuclear magnetic resonance(NMR)and X-ray photoelectron spectroscopy(XPS)analysis,which results in a high initial activity and hydrogen efficiency;while the high surface acidity generated by these Ti species leads to a continuous decrease in the activity and the propylene oxide(PO)selectivity during the reaction.As the amount of urea gradually increases,the TS-1-B samples present the reduced surface defects and defective and unsaturated Ti species.Specially,TS-1-B-0.30U presents the weaker PO adsorption on PO-diffusion reflectance infrared Fourier transform spectra(DRIFTS),thus results in the high stable PO formation rate and selectivity over its Au catalyst.Furthermore,a flat-plate-like shape with a shorter thickness of 100 nm along the b-axis direction is observed on the urea-modified TS-1.Compared with the conventional ellipsoidal TS-1 with crystal sizes of 200 and 500 nm,the flat-plate-like TS-1-0.30U displays the less surface defects,unsaturated Ti species,the weaker Lewis acid,which is favorable for the desorption and intracrystalline diffusion of PO,thus reduces the occurrence of side reactions for the improved selectivity and stability.This work may provide a reference for developing titanium-containing materials with high activity and stability over HOPO reaction.