Rundong Wu , Li Li , Zhanghui Lu , Chunyan Sun , Lihong Cheng , Runping Ye , Rongbin Zhang , Qiang Li , Gang Feng
{"title":"DFT insights into doping and oxygen vacancy effects on CO and CO₂ adsorptions over CuAl2O4 spinel surfaces","authors":"Rundong Wu , Li Li , Zhanghui Lu , Chunyan Sun , Lihong Cheng , Runping Ye , Rongbin Zhang , Qiang Li , Gang Feng","doi":"10.1016/j.jcat.2024.115502","DOIUrl":null,"url":null,"abstract":"<div><p>Introducing transition metals into CuAl<sub>2</sub>O<sub>4</sub> spinel enhances catalyst stability and Cu sintering resistance in methanol steam reforming. Yet, the influence of doping on vacancy formation and the adsorption behaviors of CO<sub>2</sub> (the primary product) and CO (the notorious byproduct) remains unclear. Herein, we employed DFT + U to investigate CO and CO<sub>2</sub> adsorption on perfect, M-doped (Fe, Co, and Ni), and M-doped oxygen-deficient CuAl<sub>2</sub>O<sub>4</sub> spinel (1<!--> <!-->0<!--> <!-->0) and (1<!--> <!-->1<!--> <!-->0) surfaces. We find that stronger CO adsorption on (1<!--> <!-->0<!--> <!-->0) than (1<!--> <!-->1<!--> <!-->0) surfaces across all M-doped surfaces, while CO<sub>2</sub> adsorbs more stronger on (1<!--> <!-->1<!--> <!-->0) surfaces. The weakened CO adsorptions are observed on Fe and Ni-doped surfaces, demonstrating that doping plays a significant role in improving the resistance to CO poisoning. Co-doping promotes CO adsorption via a CO<sub>3</sub>-like structure on CuAl<sub>2</sub>O<sub>4</sub>(1<!--> <!-->1<!--> <!-->0) surface and boosts the CO oxidation. Furthermore, infrared spectroscopy simulation indicates that the vibrational frequencies for CO linear adsorption, formation of bent CO<sub>2</sub>- and CO<sub>3</sub>-like structures are within the ranges of 2042–2078, 1463–1566, and 1497–1816 cm<sup>−1</sup>, respectively. In addition, Ov on Ni-doped surfaces can significantly strengthen the CO<sub>2</sub> adsorption by 0.6–1.3 eV, highlighting the doping and oxygen-defect engineering in enhancing the CO<sub>2</sub> capture. This research uncovers the critical impact of metal doping and oxygen vacancies on CO and CO<sub>2</sub> adsorptions over CuAl<sub>2</sub>O<sub>4</sub> spinel catalyst, providing insights for developing catalysts with improved resistance to CO poisoning and enhanced CO oxidation which is vital for methanol steam reforming.</p></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":null,"pages":null},"PeriodicalIF":6.5000,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Catalysis","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S002195172400215X","RegionNum":1,"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
Introducing transition metals into CuAl2O4 spinel enhances catalyst stability and Cu sintering resistance in methanol steam reforming. Yet, the influence of doping on vacancy formation and the adsorption behaviors of CO2 (the primary product) and CO (the notorious byproduct) remains unclear. Herein, we employed DFT + U to investigate CO and CO2 adsorption on perfect, M-doped (Fe, Co, and Ni), and M-doped oxygen-deficient CuAl2O4 spinel (1 0 0) and (1 1 0) surfaces. We find that stronger CO adsorption on (1 0 0) than (1 1 0) surfaces across all M-doped surfaces, while CO2 adsorbs more stronger on (1 1 0) surfaces. The weakened CO adsorptions are observed on Fe and Ni-doped surfaces, demonstrating that doping plays a significant role in improving the resistance to CO poisoning. Co-doping promotes CO adsorption via a CO3-like structure on CuAl2O4(1 1 0) surface and boosts the CO oxidation. Furthermore, infrared spectroscopy simulation indicates that the vibrational frequencies for CO linear adsorption, formation of bent CO2- and CO3-like structures are within the ranges of 2042–2078, 1463–1566, and 1497–1816 cm−1, respectively. In addition, Ov on Ni-doped surfaces can significantly strengthen the CO2 adsorption by 0.6–1.3 eV, highlighting the doping and oxygen-defect engineering in enhancing the CO2 capture. This research uncovers the critical impact of metal doping and oxygen vacancies on CO and CO2 adsorptions over CuAl2O4 spinel catalyst, providing insights for developing catalysts with improved resistance to CO poisoning and enhanced CO oxidation which is vital for methanol steam reforming.
期刊介绍:
The Journal of Catalysis publishes scholarly articles on both heterogeneous and homogeneous catalysis, covering a wide range of chemical transformations. These include various types of catalysis, such as those mediated by photons, plasmons, and electrons. The focus of the studies is to understand the relationship between catalytic function and the underlying chemical properties of surfaces and metal complexes.
The articles in the journal offer innovative concepts and explore the synthesis and kinetics of inorganic solids and homogeneous complexes. Furthermore, they discuss spectroscopic techniques for characterizing catalysts, investigate the interaction of probes and reacting species with catalysts, and employ theoretical methods.
The research presented in the journal should have direct relevance to the field of catalytic processes, addressing either fundamental aspects or applications of catalysis.