{"title":"Unveiling the Role of Strong Metal–Support Interactions in Gold-Catalyzed CO Oxidation on MnO2 Polymorphs","authors":"Tiantian Zhang, Jiacheng Xu, Yan Sun, Shiyu Fang, Zuliang Wu, Erhao Gao, Jiali Zhu, Wei Wang, Shuiliang Yao* and Jing Li*, ","doi":"10.1021/acs.langmuir.4c0264010.1021/acs.langmuir.4c02640","DOIUrl":null,"url":null,"abstract":"<p >The effectiveness of gold (Au)-based catalysts in CO oxidation is significantly influenced by strong metal–support interactions with surface oxygen structures, the mechanisms of which remain elusive. To investigate this property, we selected γ-MnO<sub>2</sub>, featuring Mn(-O-)<sub>2</sub>Mn and Mn–O–Mn structural motifs, and β-MnO<sub>2</sub>, characterized by Mn–O–Mn linkages, as support materials. The CO oxidation process was investigated by fabricating Au nanoparticles supported on these two MnO<sub>2</sub> polymorphs. Our findings reveal that Au supported on β-MnO<sub>2</sub> substantially enhanced CO oxidation, in stark contrast to the inhibitory effect observed with Au on γ-MnO<sub>2</sub>. Using operando diffuse reflectance infrared Fourier transform spectroscopy coupled with mass spectrometry, we detected an increase in the production of surface-adsorbed oxygen following Au deposition on β-MnO<sub>2</sub>. Conversely, Au supported on γ-MnO<sub>2</sub> resulted in a diminished capacity for surface oxygen adsorption. The presence of Au<sup>+</sup> and Mn<sup>2+</sup> ions was identified as pivotal for CO oxidation. Moreover, the engagement of the Mn(-O-)<sub>2</sub>Mn structure in the reaction was impaired after Au loading on γ-MnO<sub>2</sub>, and the regeneration of the Mn–O–Mn linkage was similarly hindered. We propose a mechanism for the interactions between Au and the oxygen species associated with Mn(-O-)<sub>2</sub>Mn and Mn–O–Mn structures on MnO<sub>2</sub>, offering insights into the divergent catalytic behaviors exhibited by different MnO<sub>2</sub> polymorphs.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"40 45","pages":"23739–23753 23739–23753"},"PeriodicalIF":3.7000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Langmuir","FirstCategoryId":"92","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.langmuir.4c02640","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The effectiveness of gold (Au)-based catalysts in CO oxidation is significantly influenced by strong metal–support interactions with surface oxygen structures, the mechanisms of which remain elusive. To investigate this property, we selected γ-MnO2, featuring Mn(-O-)2Mn and Mn–O–Mn structural motifs, and β-MnO2, characterized by Mn–O–Mn linkages, as support materials. The CO oxidation process was investigated by fabricating Au nanoparticles supported on these two MnO2 polymorphs. Our findings reveal that Au supported on β-MnO2 substantially enhanced CO oxidation, in stark contrast to the inhibitory effect observed with Au on γ-MnO2. Using operando diffuse reflectance infrared Fourier transform spectroscopy coupled with mass spectrometry, we detected an increase in the production of surface-adsorbed oxygen following Au deposition on β-MnO2. Conversely, Au supported on γ-MnO2 resulted in a diminished capacity for surface oxygen adsorption. The presence of Au+ and Mn2+ ions was identified as pivotal for CO oxidation. Moreover, the engagement of the Mn(-O-)2Mn structure in the reaction was impaired after Au loading on γ-MnO2, and the regeneration of the Mn–O–Mn linkage was similarly hindered. We propose a mechanism for the interactions between Au and the oxygen species associated with Mn(-O-)2Mn and Mn–O–Mn structures on MnO2, offering insights into the divergent catalytic behaviors exhibited by different MnO2 polymorphs.
期刊介绍:
Langmuir is an interdisciplinary journal publishing articles in the following subject categories:
Colloids: surfactants and self-assembly, dispersions, emulsions, foams
Interfaces: adsorption, reactions, films, forces
Biological Interfaces: biocolloids, biomolecular and biomimetic materials
Materials: nano- and mesostructured materials, polymers, gels, liquid crystals
Electrochemistry: interfacial charge transfer, charge transport, electrocatalysis, electrokinetic phenomena, bioelectrochemistry
Devices and Applications: sensors, fluidics, patterning, catalysis, photonic crystals
However, when high-impact, original work is submitted that does not fit within the above categories, decisions to accept or decline such papers will be based on one criteria: What Would Irving Do?
Langmuir ranks #2 in citations out of 136 journals in the category of Physical Chemistry with 113,157 total citations. The journal received an Impact Factor of 4.384*.
This journal is also indexed in the categories of Materials Science (ranked #1) and Multidisciplinary Chemistry (ranked #5).