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Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets through a Transient CO‐O Complex **
Author(s) -
GarciaMartinez Fernando,
GarcíaFernández Carlos,
Simonovis Juan Pablo,
Hunt Adrian,
Walter Andrew,
Waluyo Iradwikanari,
Bertram Florian,
Merte Lindsay R.,
Shipilin Mikhail,
Pfaff Sebastian,
Blomberg Sara,
Zetterberg Johan,
Gustafson Johan,
Lundgren Edvin,
SánchezPortal Daniel,
Schiller Frederik,
Ortega J. Enrique
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202007195
Subject(s) - chemisorption , catalysis , transition metal , desorption , chemistry , crystal (programming language) , redox , single crystal , metal , crystallography , analytical chemistry (journal) , chemical physics , materials science , inorganic chemistry , adsorption , biochemistry , organic chemistry , chromatography , computer science , programming language
The catalytic oxidation of CO on transition metals, such as Pt, is commonly viewed as a sharp transition from the CO‐inhibited surface to the active metal, covered with O. However, we find that minor amounts of O are present in the CO‐poisoned layer that explain why, surprisingly, CO desorbs at stepped and flat Pt crystal planes at once, regardless of the reaction conditions. Using near‐ambient pressure X‐ray photoemission and a curved Pt(111) crystal we probe the chemical composition at surfaces with variable step density during the CO oxidation reaction. Analysis of C and O core levels across the curved crystal reveals that, right before light‐off, subsurface O builds up within (111) terraces. This is key to trigger the simultaneous ignition of the catalytic reaction at different Pt surfaces: a CO‐Pt‐O complex is formed that equals the CO chemisorption energy at terraces and steps, leading to the abrupt desorption of poisoning CO from all crystal facets at the same temperature.