EXAFS/XANES, chemisorption and IR investigations of colloidal Pt/Rh bimetallic catalysts

Autor: J. Rothe, Werner Brijoux, K. Siepen, Josef Hormes, Helmut Bönnemann
Rok vydání: 2000
Předmět:
Zdroj: Applied Organometallic Chemistry. 14:549-556
ISSN: 1099-0739
0268-2605
DOI: 10.1002/1099-0739(200010)14:10<549::aid-aoc37>3.0.co;2-j
Popis: Bimetallic Pt/Rh heterogeneous catalysts based on nanoscaled colloids supported on activated charcoal have been shown to exhibit maximum activity in hydrogenation of butyronitrile at a composition of 10 atom% Pt and 90 atom% Rh in the metallic core. This synergetic effect has to be traced back to the special structure of the bimetallic nanoparticles as elucidated by X-ray spectroscopy and CO chemisorption. The surface of Pt/Rh particles was investigated by CO chemisorption combined with IR spectroscopy. It has been shown that a Pt 10 Rh 90 colloid exhibits the maximum ability to chemisorb CO, compared with other compositions. Based on the detection of the different types of bonding of CO molecules to the metal surface and the EXAFS results, our measurements reveal surface enrichment of the Rh component. The surface structure of the particles, which varies with the elemental composition, and the presence of a Pt-dominated core influence the CO chemisorption ability as well as the hydrogenation efficiency of the Pt/Rh colloid catalysts.
Databáze: OpenAIRE
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