Article
Hydrogen and Deuterium Exchange on Pt(111) and Its Poisoning by Carbon Monoxide Studied by Surface Sensitive High-Pressure Techniques
Journal of the American Chemical Society
(2006)
Abstract
Catalytic hydrogen/deuterium exchange on a platinum (111) single crystal and its poisoning with carbon monoxide was studied using scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), sum frequency generation vibrational spectroscopy (SFG), and mass spectrometry under reaction conditions at pressures in the mTorr to atmospheric range. At 298 K and in the presence of 200 mTorr of hydrogen and 20 mTorr of deuterium the surface is catalytically active, producing HD with activation energy of 5.3 kcal/mol. Addition of 5 mTorr of CO stops the reaction completely. In situ STM images reveal an ordered surface structure of chemisorbed CO. At 353 K the addition of 5 mTorr of CO slows the reaction by 3 orders of magnitude, but HD production continues with an activation energy of 17.4 kcal/mol. Changes in coverage and adsorption site of CO were followed by XPS and SFG up to a temperature of 480 K. From these data, a CO dominated, mobile and catalytically active surface model is proposed.
Keywords
- Lawrence Berkeley National Laboratory
Disciplines
Publication Date
October, 2006
Citation Information
Max Montano, Kaitlin M. Bratlie, Miquel Salmeron and Gabor A. Somorjai. "Hydrogen and Deuterium Exchange on Pt(111) and Its Poisoning by Carbon Monoxide Studied by Surface Sensitive High-Pressure Techniques" Journal of the American Chemical Society Vol. 128 Iss. 40 (2006) Available at: http://works.bepress.com/kaitlin_bratlie/2/
This article is from Journal of the American Chemical Society 128 (2006):13229-13234, doi: 10.1021/ja063703a. Copyright 2006 American Chemical Society. Posted with permission.