Lucci, FR;
Darby, MT;
Mattera, MF;
Ivimey, CJ;
Therrien, AJ;
Michaelides, A;
Stamatakis, M;
(2016)
Controlling Hydrogen Activation, Spillover, and Desorption with Pd-Au Single-Atom Alloys.
Journal of Physical Chemistry Letters
, 7
(3)
pp. 480-485.
10.1021/acs.jpclett.5b02400.
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Abstract
Key descriptors in hydrogenation catalysis are the nature of the active sites for H2 activation and the adsorption strength of H atoms to the surface. Using atomically resolved model systems of dilute Pd-Au surface alloys and density functional theory calculations, we determine key aspects of H2 activation, diffusion, and desorption. Pd monomers in a Au(111) surface catalyze the dissociative adsorption of H2 at temperatures as low as 85 K, a process previously expected to require contiguous Pd sites. H atoms preside at the Pd sites and desorb at temperatures significantly lower than those from pure Pd (175 versus 310 K). This facile H2 activation and weak adsorption of H atom intermediates are key requirements for active and selective hydrogenations. We also demonstrate weak adsorption of CO, a common catalyst poison, which is sufficient to force H atoms to spill over from Pd to Au sites, as evidenced by low-temperature H2 desorption.
| Type: | Article |
|---|---|
| Title: | Controlling Hydrogen Activation, Spillover, and Desorption with Pd-Au Single-Atom Alloys |
| Location: | United States |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1021/acs.jpclett.5b02400 |
| Publisher version: | http://dx.doi.org/10.1021/acs.jpclett.5b02400 |
| Language: | English |
| Additional information: | This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal Physical Chemistry Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.jpclett.5b02400. |
| Keywords: | Bimetallic alloys, temperature programmed desorption, scanning tunneling microscopy, density functional theory, hydrogenation |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1475584 |
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