A self-adjusting platinum surface for acetone hydrogenation
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- Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemical and Biological Engineering, and Dept. of Energy, Great Lakes Bioenergy Research Center; University of Wisconsin-Madison Department of Chemical and Biological Engineering
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemical and Biological Engineering
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemical and Biological Engineering, and Dept. of Energy, Great Lakes Bioenergy Research Center
We show that platinum displays a self-adjusting surface that is active for the hydrogenation of acetone over a wide range of reaction conditions. Reaction kinetics measurements under steady-state and transient conditions at temperatures near 350 K, electronic structure calculations employing density-functional theory, and microkinetic modeling were employed to study this behavior over supported platinum catalysts. The importance of surface coverage effects was highlighted by evaluating the transient response of isopropanol formation following either removal of the reactant ketone from the feed, or its substitution with a similarly structured species. The extent to which adsorbed intermediates that lead to the formation of isopropanol were removed from the catalytic surface was observed to be higher following ketone substitution in comparison to its removal, indicating that surface species leading to isopropanol become more strongly adsorbed on the surface as the coverage decreases during the desorption experiment. This phenomenon occurs as a result of adsorbate–adsorbate repulsive interactions on the catalyst surface which adjust with respect to the reaction conditions. Reaction kinetics parameters obtained experimentally were in agreement with those predicted by microkinetic modeling when the binding energies, activation energies, and entropies of adsorbed species and transition states were expressed as a function of surface coverage of the most abundant surface intermediate (MASI, C3H6OH*). It is important that these effects of surface coverage be incorporated dynamically in the microkinetic model (e.g., using the Bragg–Williams approximation) to describe the experimental data over a wide range of acetone partial pressures.
- Research Organization:
- Great Lakes Bioenergy Research Center (GLBRC), Madison, WI (United States); Univ. of Wisconsin, Madison, WI (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- FG02-05ER15731; SC0014058; SC0018409
- OSTI ID:
- 1600938
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 7 Vol. 117; ISSN 0027-8424
- Publisher:
- National Academy of SciencesCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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