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Cu-doped zeolites for catalytic oxidative carbonylation: The role of Brønsted acids

Paper ID Volume ID Publish Year Pages File Format Full-Text
41180 45879 2012 7 PDF Available
Title
Cu-doped zeolites for catalytic oxidative carbonylation: The role of Brønsted acids
Abstract

The aim of this work was to establish the role of Brønsted acidic sites in Cu-doped zeolites for the oxidative carbonylation of ethanol to diethyl carbonate (DEC). In order to eliminate the influences of other factors such as channel structure, faujasite (FAU) with different SiO2/Al2O3 ratios and Beta before and after passivation were investigated. Fourier Transform infrared spectroscopy (FTIR) of pyridine adsorption indicated that all of Brønsted acidic sites were exchanged with CuCl to form effective active sites for oxidative carbonylation. Characterization data showed that passivation on Beta zeolites has little effect on surface area and pore volume distribution except Brønsted acidic sites. The relationship between Brønsted acidic sites and catalyst activity was built on different types of zeolite supports. Diffuse reflectance infrared Fourier transform spectroscopy (DIRFTS) of CO adsorption revealed that the location of Cu active sites was related to the distribution of Brønsted acidic sites, which also influenced catalytic performance of oxidative carbonylation.

Graphical abstract.Figure optionsDownload full-size imageDownload high-quality image (166 K)Download as PowerPoint slideHighlights► Nature of Brønsted acidic sites in Cu-doped zeolites was investigated. ► A quantitative relationship was drawn between Brønsted sites and reactivity. ► Effects of Brønsted acidic sites on anchoring Cu sites were examined.

Keywords
Oxidative carbonylation; Cu-doped zeolite; Brønsted acids; Dialkyl carbonate
First Page Preview
Cu-doped zeolites for catalytic oxidative carbonylation: The role of Brønsted acids
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volumes 417–418, 29 February 2012, Pages 236–242
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis