Publication Date

5-8-2019

Department

Ames Laboratory; Chemistry

Campus Units

Ames Laboratory, Chemistry

OSTI ID+

1513015

Report Number

IS-J 10344

DOI

10.1016/j.jcat.2019.04.013

Journal Title

Journal of Catalysis

Volume Number

374

First Page

136

Last Page

142

Abstract

Intermetallic compounds are unique catalyst platforms for mechanistic studies and industrial applications, because of their ordered structures in comparison to random alloys. Despite the intrinsically defined stoichiometry of intermetallic compounds, compositional deviations can still occur in intermetallic catalysts. The location of the extra metal atoms could differ the catalytic properties of intermetallic compounds with non-stoichiometric composition if those metal atoms end up on/near the surface. In this study, we synthesized PtSn intermetallic compounds with accurate stoichiometry and slightly Pt-/Sn-rich compositions. We used furfural hydrogenation and acetylene semi-hydrogenation as probe reactions to investigate the surface structures of PtSn intermetallic catalysts after reduction at different temperatures. Even though the intermetallic PtSn is the major bulk phase among non-stoichiometric compositions, the intermetallic PtSn surface can only be observed under the high-temperature reduction in Sn-rich PtSn intermetallic nanoparticles (iNPs), while the Pt-rich PtSn iNPs show Pt-rich-surfaces regardless of reduction temperatures. Four structural models were constructed based on the comprehensive surface and bulk characterizations. This work extends the understanding of intermetallic catalysts with non-stoichiometric compositions to tailor the intermetallic surface structures for catalysis.

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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