Weijia Ren, Qifeng Xin, Zhesheng Hua, Zhong Zheng, Lifeng Xiao, Shaojun Liu, Chenghang Zheng, Yang Yang
{"title":"粉煤灰衍生Mn-Ce/沸石X上NH3-SCR反应性能及机理研究","authors":"Weijia Ren, Qifeng Xin, Zhesheng Hua, Zhong Zheng, Lifeng Xiao, Shaojun Liu, Chenghang Zheng, Yang Yang","doi":"10.4209/aaqr.230032","DOIUrl":null,"url":null,"abstract":"Zeolite X was synthesized from fly ash under optimized conditions, which was supported with Mn, Ce, and Mn-Ce respectively. Fly ash-derived zeolite X catalysts exhibited similar catalytic performance as compared with the commercial zeolite X catalyst. XRD, N 2 adsorption, SEM, XPS, and H 2 -TPR were used to investigate the relationship among the structure, physicochemical properties, and catalytic activities of the catalysts. Finally, the mechanism of NH 3 -SCR reaction on Mn-Ce/zeolite X was systematically performed by using diffused reflectance infrared Fourier transform spectroscopy (DRIFTS). The characterization results showed that the amorphous structure and good dispersion between Mn and Ce on the surface of the zeolite changed the electronic properties of the active components, improved its low-temperature catalytic activity, brought it characteristics of Mn and Ce at the same time, and broaden the reaction temperature range. The NO conversion rate of Mn-Ce-FX catalyst remained above 80% at 200 ° C–300 ° C. From DRIFTS we suggest that Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism are simultaneously carried out on the catalyst surface. According to the FTIR results, the Eley-Rideal mechanism has a great influence on the reaction below 250 ° C, and the Brønsted acid sites adsorb a large amount of NH 3 , resulting in an excellent low-temperature activity. When above 250 ° C, Langmuir-Hinshelwood mechanism plays a dominant role. The nitrates on the surface gradually convert to bidentate nitrates, impeding the SCR reaction, could be one of the reasons for reducing the high-temperature activity.","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":""},"PeriodicalIF":2.5000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Research on Performance and Mechanism of the NH3-SCR Reaction over Fly Ash-derived Mn-Ce/Zeolite X\",\"authors\":\"Weijia Ren, Qifeng Xin, Zhesheng Hua, Zhong Zheng, Lifeng Xiao, Shaojun Liu, Chenghang Zheng, Yang Yang\",\"doi\":\"10.4209/aaqr.230032\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Zeolite X was synthesized from fly ash under optimized conditions, which was supported with Mn, Ce, and Mn-Ce respectively. Fly ash-derived zeolite X catalysts exhibited similar catalytic performance as compared with the commercial zeolite X catalyst. XRD, N 2 adsorption, SEM, XPS, and H 2 -TPR were used to investigate the relationship among the structure, physicochemical properties, and catalytic activities of the catalysts. Finally, the mechanism of NH 3 -SCR reaction on Mn-Ce/zeolite X was systematically performed by using diffused reflectance infrared Fourier transform spectroscopy (DRIFTS). The characterization results showed that the amorphous structure and good dispersion between Mn and Ce on the surface of the zeolite changed the electronic properties of the active components, improved its low-temperature catalytic activity, brought it characteristics of Mn and Ce at the same time, and broaden the reaction temperature range. The NO conversion rate of Mn-Ce-FX catalyst remained above 80% at 200 ° C–300 ° C. From DRIFTS we suggest that Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism are simultaneously carried out on the catalyst surface. According to the FTIR results, the Eley-Rideal mechanism has a great influence on the reaction below 250 ° C, and the Brønsted acid sites adsorb a large amount of NH 3 , resulting in an excellent low-temperature activity. When above 250 ° C, Langmuir-Hinshelwood mechanism plays a dominant role. The nitrates on the surface gradually convert to bidentate nitrates, impeding the SCR reaction, could be one of the reasons for reducing the high-temperature activity.\",\"PeriodicalId\":7402,\"journal\":{\"name\":\"Aerosol and Air Quality Research\",\"volume\":\"1 1\",\"pages\":\"\"},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2023-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Aerosol and Air Quality Research\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://doi.org/10.4209/aaqr.230032\",\"RegionNum\":4,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Aerosol and Air Quality Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.4209/aaqr.230032","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
Research on Performance and Mechanism of the NH3-SCR Reaction over Fly Ash-derived Mn-Ce/Zeolite X
Zeolite X was synthesized from fly ash under optimized conditions, which was supported with Mn, Ce, and Mn-Ce respectively. Fly ash-derived zeolite X catalysts exhibited similar catalytic performance as compared with the commercial zeolite X catalyst. XRD, N 2 adsorption, SEM, XPS, and H 2 -TPR were used to investigate the relationship among the structure, physicochemical properties, and catalytic activities of the catalysts. Finally, the mechanism of NH 3 -SCR reaction on Mn-Ce/zeolite X was systematically performed by using diffused reflectance infrared Fourier transform spectroscopy (DRIFTS). The characterization results showed that the amorphous structure and good dispersion between Mn and Ce on the surface of the zeolite changed the electronic properties of the active components, improved its low-temperature catalytic activity, brought it characteristics of Mn and Ce at the same time, and broaden the reaction temperature range. The NO conversion rate of Mn-Ce-FX catalyst remained above 80% at 200 ° C–300 ° C. From DRIFTS we suggest that Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism are simultaneously carried out on the catalyst surface. According to the FTIR results, the Eley-Rideal mechanism has a great influence on the reaction below 250 ° C, and the Brønsted acid sites adsorb a large amount of NH 3 , resulting in an excellent low-temperature activity. When above 250 ° C, Langmuir-Hinshelwood mechanism plays a dominant role. The nitrates on the surface gradually convert to bidentate nitrates, impeding the SCR reaction, could be one of the reasons for reducing the high-temperature activity.
期刊介绍:
The international journal of Aerosol and Air Quality Research (AAQR) covers all aspects of aerosol science and technology, atmospheric science and air quality related issues. It encompasses a multi-disciplinary field, including:
- Aerosol, air quality, atmospheric chemistry and global change;
- Air toxics (hazardous air pollutants (HAPs), persistent organic pollutants (POPs)) - Sources, control, transport and fate, human exposure;
- Nanoparticle and nanotechnology;
- Sources, combustion, thermal decomposition, emission, properties, behavior, formation, transport, deposition, measurement and analysis;
- Effects on the environments;
- Air quality and human health;
- Bioaerosols;
- Indoor air quality;
- Energy and air pollution;
- Pollution control technologies;
- Invention and improvement of sampling instruments and technologies;
- Optical/radiative properties and remote sensing;
- Carbon dioxide emission, capture, storage and utilization; novel methods for the reduction of carbon dioxide emission;
- Other topics related to aerosol and air quality.