用红外光谱法研究 Cu-Faujasites 中 Cu 物种的还原和氧化。

Reduction and Oxidation of Cu Species in Cu-Faujasites Studied by IR Spectroscopy.

机构信息

Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Krakow, Poland.

出版信息

Molecules. 2020 Oct 16;25(20):4765. doi: 10.3390/molecules25204765.

DOI:10.3390/molecules25204765

PMID:33081409

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7587588/

Abstract

The process of reduction (by hydrogen and ethanol) and oxidation (by oxygen and NO) of Cu sites in dealuminated faujasite-type zeolites (of Si/Al = 31) was studied by infrared (IR) spectroscopy with CO (for Cu) and NO (for Cu) as probe molecules. Two zeolites were studied: one of them contained mostly Cu, whereas another one contained mostly Cu and Cu The susceptibility of various forms of Cu for reduction were investigated. IR experiments of CO sorption evidenced that Cu was more prone for the reduction than Cu According to NO sorption studies, Cu was reduced in the first order before Cu Ethanol reduced mostly Cu and, also, some amounts of Cu. The treatment with oxygen caused the oxidation of Cu (both Cu and Cu) to Cu. The adsorption of NO at 190K produced Cu(NO) dinitrosyls, but heating to room temperature transformed dinitrosyls to mononitrosyls and increased the Cu content.

摘要

采用红外光谱（IR）技术，以 CO（用于 Cu）和 NO（用于 Cu）作为探针分子，研究了脱铝丝光沸石型沸石（Si/Al=31）中 Cu 位的还原（由氢气和乙醇引起）和氧化（由氧气和 NO 引起）过程。研究了两种沸石：一种主要含 Cu，另一种主要含 Cu 和 Cu。研究了各种形式的 Cu 还原的敏感性。CO 吸附的 IR 实验表明，Cu 比 Cu 更容易还原。根据 NO 吸附研究，Cu 先按一级反应还原，然后才是 Cu。乙醇主要还原 Cu，也还原一定量的 Cu。氧气处理导致 Cu（Cu 和 Cu）氧化为 Cu。在 190K 下吸附 NO 生成 Cu(NO)二亚硝酰基，但加热至室温将二亚硝酰基转化为单硝酰基并增加 Cu 含量。