Rh K-Edge High-Energy-Resolution Fluorescence-Detected X-ray Absorption Near-Edge Structure Spectroscopy Reveals Deactivated RhAlOx Structure in Aged Rh/γ-Al2O3 Catalyst

IF 11.3 1区化学 Q1 CHEMISTRY, PHYSICAL

ACS Catalysis Pub Date : 2025-04-06 DOI:10.1021/acscatal.5c00633

Mizuki Sato, Keisuke Awaya, Masayuki Tsushida, Masato Machida, Nozomu Hiraoka, Junya Ohyama

{"title":"Rh K-Edge High-Energy-Resolution Fluorescence-Detected X-ray Absorption Near-Edge Structure Spectroscopy Reveals Deactivated RhAlOx Structure in Aged Rh/γ-Al2O3 Catalyst","authors":"Mizuki Sato, Keisuke Awaya, Masayuki Tsushida, Masato Machida, Nozomu Hiraoka, Junya Ohyama","doi":"10.1021/acscatal.5c00633","DOIUrl":null,"url":null,"abstract":"Rh K-edge high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge structure (XANES) spectroscopy was used to investigate the deactivated structure in an aged Rh/γ-Al2O3 catalyst for automotive gas purification, which has been difficult to identify using conventional XANES spectroscopy. HERFD-XANES spectroscopy uncovered the distinct spectral features of the deactivated structure in the aged Rh/γ-Al2O3 catalyst, which differed from those of supported Rh2O3 and Rh metal species. Spectral simulations of possible deactivated structures revealed the formation of Rh3+ doped in γ-Al2O3 or rhodium aluminate with octahedral coordination (octahedral RhAlOx) as the deactivated structure. The spectrum of octahedral RhAlOx was extracted from the measured spectra of fresh and aged Rh/γ-Al2O3 samples before and after H2 treatment at 600 °C using linear combination fitting analysis, thereby enabling the quantification of the fraction of octahedral RhAlOx present in the aged Rh/γ-Al2O3 catalyst. This study not only demonstrates the identification and quantification of octahedral RhAlOx in aged Rh/Al2O3 using Rh K-edge HERFD-XANES spectroscopy but also highlights the potential of HERFD-XANES spectroscopy to deepen our understanding of catalyst structures and consequently facilitate catalyst development.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"183 1","pages":""},"PeriodicalIF":11.3000,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Catalysis ","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acscatal.5c00633","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}

引用次数: 0

Abstract

Rh K-edge high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge structure (XANES) spectroscopy was used to investigate the deactivated structure in an aged Rh/γ-Al₂O₃ catalyst for automotive gas purification, which has been difficult to identify using conventional XANES spectroscopy. HERFD-XANES spectroscopy uncovered the distinct spectral features of the deactivated structure in the aged Rh/γ-Al₂O₃ catalyst, which differed from those of supported Rh₂O₃ and Rh metal species. Spectral simulations of possible deactivated structures revealed the formation of Rh³⁺ doped in γ-Al₂O₃ or rhodium aluminate with octahedral coordination (octahedral RhAlO_x) as the deactivated structure. The spectrum of octahedral RhAlO_x was extracted from the measured spectra of fresh and aged Rh/γ-Al₂O₃ samples before and after H₂ treatment at 600 °C using linear combination fitting analysis, thereby enabling the quantification of the fraction of octahedral RhAlO_x present in the aged Rh/γ-Al₂O₃ catalyst. This study not only demonstrates the identification and quantification of octahedral RhAlO_x in aged Rh/Al₂O₃ using Rh K-edge HERFD-XANES spectroscopy but also highlights the potential of HERFD-XANES spectroscopy to deepen our understanding of catalyst structures and consequently facilitate catalyst development.

Abstract Image

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

ACS Catalysis CHEMISTRY, PHYSICAL-

CiteScore

20.80

自引率

6.20%

发文量

1253

审稿时长

1.5 months

期刊介绍： ACS Catalysis is an esteemed journal that publishes original research in the fields of heterogeneous catalysis, molecular catalysis, and biocatalysis. It offers broad coverage across diverse areas such as life sciences, organometallics and synthesis, photochemistry and electrochemistry, drug discovery and synthesis, materials science, environmental protection, polymer discovery and synthesis, and energy and fuels. The scope of the journal is to showcase innovative work in various aspects of catalysis. This includes new reactions and novel synthetic approaches utilizing known catalysts, the discovery or modification of new catalysts, elucidation of catalytic mechanisms through cutting-edge investigations, practical enhancements of existing processes, as well as conceptual advances in the field. Contributions to ACS Catalysis can encompass both experimental and theoretical research focused on catalytic molecules, macromolecules, and materials that exhibit catalytic turnover.