Enhanced Catalytic Activity and SO2/H2O Tolerance for Selective Catalytic Reduction of NOx with NH3 over Titanate Nanotubes Supported MnOx–CeO2 Catalyst at Low Temperature
{"title":"Enhanced Catalytic Activity and SO2/H2O Tolerance for Selective Catalytic Reduction of NOx with NH3 over Titanate Nanotubes Supported MnOx–CeO2 Catalyst at Low Temperature","authors":"Zhuping Jiang, Qiulin Wang, Yuzhou Cai","doi":"10.1007/s10563-022-09356-w","DOIUrl":null,"url":null,"abstract":"<div><p>An environment-friendly selective catalytic reduction (SCR) catalyst with high catalytic activity and strong anti-poisoning performance at low temperature is strongly needed to achieve the wide application of low temperature NH<sub>3</sub>-SCR technology. Selection of appropriate carrier is one of the most important measures to improve catalytic activity as well as anti-poisoning capability of SCR catalyst. Manganese oxide-cerium oxide supported on traditional titanium dioxide (denoted as MnCe/TiO<sub>2</sub>) and titanate nanotubes (denoted as MnCe/TiNTs) were prepared by impregnation method and their catalytic activities towards NH<sub>3</sub>-SCR of NO were evaluated in flue gas with or without SO<sub>2</sub> & H<sub>2</sub>O. The results indicate that TiNTs with optimum morphology and microstructure can be obtained when P25 TiO<sub>2</sub> is hydrothermally treated at 130 °C for 24 h. Supporting MnO<sub><i>x</i></sub>–CeO<sub>2</sub> composite on TiNTs not only enhances the catalytic activity at low temperature, but also improves N<sub>2</sub> selectivity and widens active temperature window of catalyst. The main reason is the large specific surface area as well as the unique hollow tubular structure of TiNTs facilitates high dispersion of catalytic active components on the inner and outer walls of TiNTs, which enriches surface acid sites and surface reactive oxygen species to fulfill low temperature SCR reaction cycle. Moreover, TiNTs significantly enhances the SO<sub>2</sub> & H<sub>2</sub>O tolerance of catalyst, for the competitive adsorption between SO<sub>2</sub>, H<sub>2</sub>O and reactants is alleviated and the deposition of ammonium sulphate or ammonium bisulphate becomes more difficult on MnCe/TiNTs catalyst. Besides, the confinement effect of TiNTs makes partial toxicants be trapped inside the tubular channel of TiNTs. So that protects the active components, which are distributed on the out wall of TiNTs, from being poisoned.</p></div>","PeriodicalId":509,"journal":{"name":"Catalysis Surveys from Asia","volume":null,"pages":null},"PeriodicalIF":2.1000,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catalysis Surveys from Asia","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s10563-022-09356-w","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 5
Abstract
An environment-friendly selective catalytic reduction (SCR) catalyst with high catalytic activity and strong anti-poisoning performance at low temperature is strongly needed to achieve the wide application of low temperature NH3-SCR technology. Selection of appropriate carrier is one of the most important measures to improve catalytic activity as well as anti-poisoning capability of SCR catalyst. Manganese oxide-cerium oxide supported on traditional titanium dioxide (denoted as MnCe/TiO2) and titanate nanotubes (denoted as MnCe/TiNTs) were prepared by impregnation method and their catalytic activities towards NH3-SCR of NO were evaluated in flue gas with or without SO2 & H2O. The results indicate that TiNTs with optimum morphology and microstructure can be obtained when P25 TiO2 is hydrothermally treated at 130 °C for 24 h. Supporting MnOx–CeO2 composite on TiNTs not only enhances the catalytic activity at low temperature, but also improves N2 selectivity and widens active temperature window of catalyst. The main reason is the large specific surface area as well as the unique hollow tubular structure of TiNTs facilitates high dispersion of catalytic active components on the inner and outer walls of TiNTs, which enriches surface acid sites and surface reactive oxygen species to fulfill low temperature SCR reaction cycle. Moreover, TiNTs significantly enhances the SO2 & H2O tolerance of catalyst, for the competitive adsorption between SO2, H2O and reactants is alleviated and the deposition of ammonium sulphate or ammonium bisulphate becomes more difficult on MnCe/TiNTs catalyst. Besides, the confinement effect of TiNTs makes partial toxicants be trapped inside the tubular channel of TiNTs. So that protects the active components, which are distributed on the out wall of TiNTs, from being poisoned.
期刊介绍:
Early dissemination of important findings from Asia which may lead to new concepts in catalyst design is the main aim of this journal. Rapid, invited, short reviews and perspectives from academia and industry will constitute the major part of Catalysis Surveys from Asia . Surveys of recent progress and activities in catalytic science and technology and related areas in Asia will be covered regularly as well. We would appreciate critical comments from colleagues throughout the world about articles in Catalysis Surveys from Asia . If requested and thought appropriate, the comments will be included in the journal. We will be very happy if this journal stimulates global communication between scientists and engineers in the world of catalysis.