Structure Chemical Composition And Reactivity Correlations during the In Situ Oxidation of 2-Propanol

Journal Article · Sat Dec 31 04:00:00 EST 2011 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja200178f· OSTI ID:1041916

Paredis, K; Ono, L; Mostafa, S; Li, L; Zhang, Z; Yang, J; Barrio, L; Frenkel, A; Cuenya, B Roldan

Unraveling the complex interaction between catalysts and reactants under operando conditions is a key step toward gaining fundamental insight in catalysis. We report the evolution of the structure and chemical composition of size-selected micellar Pt nanoparticles ({approx}1 nm) supported on nanocrystalline {gamma}-Al{sub 2}O{sub 3} during the catalytic oxidation of 2-propanol using X-ray absorption fine-structure spectroscopy. Platinum oxides were found to be the active species for the partial oxidation of 2-propanol (<140 C), while the complete oxidation (>140 C) is initially catalyzed by oxygen-covered metallic Pt nanoparticles, which were found to regrow a thin surface oxide layer above 200 C. The intermediate reaction regime, where the partial and complete oxidation pathways coexist, is characterized by the decomposition of the Pt oxide species due to the production of reducing intermediates and the blocking of O{sub 2} adsorption sites on the nanoparticle surface. The high catalytic activity and low onset reaction temperature displayed by our small Pt particles for the oxidation of 2-propanol is attributed to the large amount of edge and corner sites available, which facilitate the formation of reactive surface oxides. Our findings highlight the decisive role of the nanoparticle structure and chemical state in oxidation catalytic reactions.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: USDOE SC OFFICE OF SCIENCE (SC)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1041916
• Report Number(s): BNL--97594-2012-JA
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 17 Vol. 133; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABSORPTION
ADSORPTION
CATALYSIS
CATALYSTS
CHEMICAL COMPOSITION
CHEMICAL STATE
FINE STRUCTURE
OXIDATION
OXIDES
PLATINUM OXIDES
PRODUCTION
PROPANOLS
SPECTROSCOPY