Ab-initio all electron relativistic calculations for Co-Pt3Sn(111) system for preferential oxidation of Co

2007 AIChE Annual Meeting, Salt Lake City, UT, Amerika Birleşik Devletleri, 4 - 09 Kasım 2007, (Tam Metin Bildiri)

Yayın Türü: Bildiri / Tam Metin Bildiri
Basıldığı Şehir: Salt Lake City, UT
Basıldığı Ülke: Amerika Birleşik Devletleri
Boğaziçi Üniversitesi Adresli: Evet

Özet

The lack of distribution network and storage problems limits the use of stored hydrogen in fuel cell applications. The adsorption properties of Pt3Sn(111) alloy were studied using all-electron relativistic DFT calculations. AER calculations made a correct estimation of the site preference of adsorbed CO on the metal surface, occupation of atop sites followed by occupation of bridge sites, in correspondence with experimental findings in the literature. The decreased activation barrier of the reaction on the alloy surface describes the reasons of the increased activity of Pt-alloy compared to monometallic Pt. Pt3Sn was chosen as a model considering its high activity and selectivity, stability in PROX reaction, and has one of the highest catalytic activities for CO electrooxidation. The most favorable site, according to the results of AER calculations, was indeed atop site, followed by occupation of bridge sites, in correlation with the experimental findings in the literature. The interaction between the adsorbed CO and O was short range and there was not a pronounced change in the binding strength of one reactant when the second reactant adsorbs on the surface. The activation barrier of CO oxidation reaction in this way was lower on Pt3Sn(111) than it was on Pt(111) which described the reasons of the increased activity of bimetallic Pt alloy towards CO oxidation reaction. This is an abstract of a paper presented at the AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).