Anastasia Yu. Molokova, Davide Salusso, Elisa Borfecchia, Fei Wen, Stefano Magliocco, Silvia Bordiga, Ton V. W. Janssens, Kirill A. Lomachenko, Gloria Berlier
{"title":"The chemical nature of SO2 poisoning of Cu-CHA-based SCR catalysts for NOx removal in diesel exhausts","authors":"Anastasia Yu. Molokova, Davide Salusso, Elisa Borfecchia, Fei Wen, Stefano Magliocco, Silvia Bordiga, Ton V. W. Janssens, Kirill A. Lomachenko, Gloria Berlier","doi":"10.1039/d4cy00792a","DOIUrl":null,"url":null,"abstract":"This study addresses the impact of SO<small><sub>2</sub></small> exposure on the catalytic performance of a Cu-chabazite-based SCR catalyst, as used in diesel exhausts, to reduce the emission of NOx through the NH<small><sub>3</sub></small>-SCR reaction. The SCR activity is determined by a reaction of NO with the [Cu<small><sub>2</sub></small><small><sup>II</sup></small>(NH<small><sub>3</sub></small>)<small><sub>4</sub></small>O<small><sub>2</sub></small>]<small><sup>2+</sup></small> intermediate. The same intermediate is also the most reactive Cu-species towards SO<small><sub>2</sub></small>. We demonstrate here that the reaction with NO at 200 °C is limited after exposure of the [Cu<small><sub>2</sub></small><small><sup>II</sup></small>(NH<small><sub>3</sub></small>)<small><sub>4</sub></small>O<small><sub>2</sub></small>]<small><sup>2+</sup></small> complex to SO<small><sub>2</sub></small> or SO<small><sub>2</sub></small>/O<small><sub>2</sub></small>. Heating the catalyst to 300 °C in NO restores the reaction, albeit at a significantly lower rate. The lower reactivity towards NO indicates that exposure of [Cu<small><sub>2</sub></small><small><sup>II</sup></small>(NH<small><sub>3</sub></small>)<small><sub>4</sub></small>O<small><sub>2</sub></small>]<small><sup>2+</sup></small> to SO<small><sub>2</sub></small> induces changes in the chemistry of Cu in the catalyst. This implies that poisoning of Cu-chabazite catalysts by SO<small><sub>2</sub></small> is, at least in part, of the chemical nature, and may be not limited to the physical pore blocking.","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":null,"pages":null},"PeriodicalIF":4.4000,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catalysis Science & Technology","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d4cy00792a","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
This study addresses the impact of SO2 exposure on the catalytic performance of a Cu-chabazite-based SCR catalyst, as used in diesel exhausts, to reduce the emission of NOx through the NH3-SCR reaction. The SCR activity is determined by a reaction of NO with the [Cu2II(NH3)4O2]2+ intermediate. The same intermediate is also the most reactive Cu-species towards SO2. We demonstrate here that the reaction with NO at 200 °C is limited after exposure of the [Cu2II(NH3)4O2]2+ complex to SO2 or SO2/O2. Heating the catalyst to 300 °C in NO restores the reaction, albeit at a significantly lower rate. The lower reactivity towards NO indicates that exposure of [Cu2II(NH3)4O2]2+ to SO2 induces changes in the chemistry of Cu in the catalyst. This implies that poisoning of Cu-chabazite catalysts by SO2 is, at least in part, of the chemical nature, and may be not limited to the physical pore blocking.
期刊介绍:
A multidisciplinary journal focusing on cutting edge research across all fundamental science and technological aspects of catalysis.
Editor-in-chief: Bert Weckhuysen
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