Alexander S. Lisitsyn, Evgenii Y. Gerasimov, Nina I. Kuznetsova
{"title":"An unexpected case of instability of metal nanoclusters","authors":"Alexander S. Lisitsyn, Evgenii Y. Gerasimov, Nina I. Kuznetsova","doi":"10.1016/j.jcat.2024.115618","DOIUrl":null,"url":null,"abstract":"It is known that Pt clusters on the surface of chlorinated alumina are highly stable against sintering in reducing or inert environments and easily disintegrate into single atoms upon heat treatments under O. However, this study reveals that partially oxidized nanoclusters tend to grow in size and reconstruct upon further annealing in an inert gas (conventionally prepared 0.25 ÷ 1 %Pt/γ-AlO-Cl samples). Even more surprisingly, the sintering takes place at rather mild conditions (He/Ar, 400–500 °C) but stops soon after it commences (within minutes). The lower the temperature of O-pretreatment (500 → 20 °C), the sharper the further drop in metal dispersion, and one to a few cycles of the consecutive treatments could be sufficient for the unique properties of Pt clusters to be lost. Possible reasons, contributing factors, and implications of the results for different catalytic systems are discussed.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":null,"pages":null},"PeriodicalIF":6.5000,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Catalysis","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1016/j.jcat.2024.115618","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
It is known that Pt clusters on the surface of chlorinated alumina are highly stable against sintering in reducing or inert environments and easily disintegrate into single atoms upon heat treatments under O. However, this study reveals that partially oxidized nanoclusters tend to grow in size and reconstruct upon further annealing in an inert gas (conventionally prepared 0.25 ÷ 1 %Pt/γ-AlO-Cl samples). Even more surprisingly, the sintering takes place at rather mild conditions (He/Ar, 400–500 °C) but stops soon after it commences (within minutes). The lower the temperature of O-pretreatment (500 → 20 °C), the sharper the further drop in metal dispersion, and one to a few cycles of the consecutive treatments could be sufficient for the unique properties of Pt clusters to be lost. Possible reasons, contributing factors, and implications of the results for different catalytic systems are discussed.
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.
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