Elucidating the Nature of the Cu(I) Active Site in CuO/TiO2 for Excellent Low-Temperature CO Oxidation

Yarong Fang; Xiao Chi; Li Li; Ji Yang; Shoujie Liu; Xingxu Lu; Wen Xiao; Liming Wang; Zhu Luo; Weiwei Yang; Siyu Hu; Juxia Xiong; Son Hoang; Hongtao Deng; Fudong Liu; Lizhi Zhang; Puxian Gao; Jun Ding; Yanbing Guo

doi:10.1021/acsami.9b18264

Elucidating the Nature of the Cu(I) Active Site in CuO/TiO₂ for Excellent Low-Temperature CO Oxidation

ACS Appl Mater Interfaces. 2020 Feb 12;12(6):7091-7101. doi: 10.1021/acsami.9b18264. Epub 2020 Feb 3.

Authors

Yarong Fang¹, Xiao Chi², Li Li¹, Ji Yang¹, Shoujie Liu¹, Xingxu Lu³, Wen Xiao⁴, Liming Wang⁵, Zhu Luo¹, Weiwei Yang¹, Siyu Hu¹, Juxia Xiong¹, Son Hoang¹, Hongtao Deng¹, Fudong Liu⁶, Lizhi Zhang¹, Puxian Gao³, Jun Ding⁴, Yanbing Guo¹

Affiliations

¹ Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental and Applied Chemistry, College of Chemistry , Central China Normal University , Wuhan 430079 , P. R. China.
² Singapore Synchrotron Light Source National University of Singapore , 5 Research Link , 117603 , Singapore.
³ Department of Chemical, Materials and Biomolecular Engineering, Institute of Materials Science , University of Connecticut , Storrs , Connecticut 06269-3136 , United States.
⁴ Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore.
⁵ CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, Institute of High Energy Physics Department of Materials Science and Engineering , Chinese Academy of Sciences , Beijing 100049 , China.
⁶ Department of Civil, Environmental, and Construction Engineering, Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT), NanoScience Technology Center , University of Central Florida , Orlando , Florida 32816 , United States.

PMID: 31931575
DOI: 10.1021/acsami.9b18264

Abstract

Stabilized Cu⁺ species have been widely considered as catalytic active sites in composite copper catalysts for catalytic reactions with industrial importance. However, few examples comprehensively explicated the origin of stabilized Cu⁺ in a low-cost and widely investigated CuO/TiO₂ system. In this study, mass producible CuO/TiO₂ catalysts with interface-stabilized Cu⁺ were prepared, which showed excellent low-temperature CO oxidation activity. A thorough characterization and theoretical calculations proved that the strong charge-transfer effect and Ti-O-Cu hybridization in Ti-doped CuO(111) at the CuO/TiO₂ interface contributed to the formation and stabilization of Cu⁺ species. The CO molecule adsorbed on Cu⁺ and reacted directly with Ti doping-promoted active lattice oxygen via a Mars-van Krevelen mechanism, leading to the enhanced low-temperature activity.

Keywords: CO adsorption; Ti-doped CuO; Ti−O−Cu hybridization; activated O; stabilized Cu+.