{"title":"Exchange reaction between cyclopentane and deuterium on evaporated nickel–copper alloy films","authors":"E. Mcmahon, P. F. Carr, J. Clarke","doi":"10.1039/J19710002012","DOIUrl":null,"url":null,"abstract":"The catalysis of cyclopentane–deuterium exchange by nickel–copper alloy films persists to low (4 atom %) nickel content. Activation energies where measurable and product distribution patterns are constant for nickel contents greater than ca. 24 atom % nickel, but below this value there is a marked increase in over-all activation energy and an even-numbered distribution pattern (maxima for tetra- and hexa-deuterio-products) develops. The latter feature is ascribed to doubly bonded intermediate described as ααββ- and ααββγγ-adsorbed. These are the species believed to be responsible for the severe self-poisoning found on pure nickel. The strength of their adsorption decreases with the increasing fraction of copper, causing initially a decrease in the extent of self-poisoning and ultimately the appearance of the even-numbered deuteriocyclopentane exchange products. These features are discussed in terms of compositional and texture changes.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"6","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1039/J19710002012","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 6
Abstract
The catalysis of cyclopentane–deuterium exchange by nickel–copper alloy films persists to low (4 atom %) nickel content. Activation energies where measurable and product distribution patterns are constant for nickel contents greater than ca. 24 atom % nickel, but below this value there is a marked increase in over-all activation energy and an even-numbered distribution pattern (maxima for tetra- and hexa-deuterio-products) develops. The latter feature is ascribed to doubly bonded intermediate described as ααββ- and ααββγγ-adsorbed. These are the species believed to be responsible for the severe self-poisoning found on pure nickel. The strength of their adsorption decreases with the increasing fraction of copper, causing initially a decrease in the extent of self-poisoning and ultimately the appearance of the even-numbered deuteriocyclopentane exchange products. These features are discussed in terms of compositional and texture changes.