Alloy Catalyst in a Reactive Environment: The Example of Ag-Cu Particles for Ethylene Epoxidation
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چکیده
منابع مشابه
Alloy catalyst in a reactive environment: the example of ag-cu particles for ethylene epoxidation.
Combining first-principles calculations and in situ photoelectron spectroscopy, we show how the composition and structure of the surface of an alloy catalyst is affected by the temperature and pressure of the reagents. The Ag-Cu alloy, recently proposed as an improved catalyst for ethylene epoxidation, forms a thin Cu-O surface oxide, while a Ag-Cu surface alloy is found not to be stable. Sever...
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Ethylene oxide, obtained through partial oxidation of ethylene, is an important compound for the chemical industry, because it is widely used as an intermediate for the production of chemicals such as ethylene glycol, which finds applications as an antifreeze and as a precursor to polymers. The oxidation of ethylene can lead either to the desired product (ethylene oxide, EO) or to the formation...
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Ag-Cu alloy catalysts for ethylene epoxidation have been shown to yield higher selectivity towards ethylene oxide compared to pure Ag, the unique catalyst employed in the industrial process. Previous studies showed that under oxidizing conditions Cu forms oxide layers on top of Ag. Using first-principles atomistic simulations based on density functional theory, we investigate the reaction mecha...
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Silver–copper alloys have been proposed as catalysts for ethylene epoxidation due to their superior selectivity compared to pure silver, the predominant catalyst for this reaction. Under reaction conditions it has been previously shown that, rather than a two-dimensional (2D) Ag–Cu alloy, a thin copper oxide-like layer forms on top of silver, and several possible surface structures were identif...
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The low selectivity of heterogeneous catalysts has been one of the critical obstacles to the wider use of heterogeneous processes in the commercial production of high value chemicals. The limited selectivity is related to a number of issues, including the lack of predictive theories that guide the discovery of the optimal catalytic site, the dearth of strategies to synthesize the targeted sites...
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ژورنال
عنوان ژورنال: Physical Review Letters
سال: 2010
ISSN: 0031-9007,1079-7114
DOI: 10.1103/physrevlett.104.035503