Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Catalytic Oxidation of CO on a Curved Pt(111) Surface : Simultaneous Ignition at All Facets through a Transient CO-O Complex

Garcia-Martinez, Fernando ; García-Fernández, Carlos ; Simonovis, Juan Pablo ; Hunt, Adrian ; Walter, Andrew ; Waluyo, Iradwikanari ; Bertram, Florian LU ; Merte, Lindsay R. LU ; Shipilin, Mikhail LU and Pfaff, Sebastian LU , et al. (2020) In Angewandte Chemie - International Edition 59(45). p.20037-20043
Abstract

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... (More)

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.

(Less)
Please use this url to cite or link to this publication:
@article{3406c102-0b9b-4fd2-9637-9dde8acecff1,
  abstract     = {{<p>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.</p>}},
  author       = {{Garcia-Martinez, Fernando and García-Fernández, Carlos and Simonovis, Juan Pablo and Hunt, Adrian and Walter, Andrew and Waluyo, Iradwikanari and Bertram, Florian and Merte, Lindsay R. and Shipilin, Mikhail and Pfaff, Sebastian and Blomberg, Sara and Zetterberg, Johan and Gustafson, Johan and Lundgren, Edvin and Sánchez-Portal, Daniel and Schiller, Frederik and Ortega, J. Enrique}},
  issn         = {{1433-7851}},
  keywords     = {{CO oxidation; curved surfaces; ignition; near-ambient pressure photoemission; subsurface oxygen}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{45}},
  pages        = {{20037--20043}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Angewandte Chemie - International Edition}},
  title        = {{Catalytic Oxidation of CO on a Curved Pt(111) Surface : Simultaneous Ignition at All Facets through a Transient CO-O Complex}},
  url          = {{http://dx.doi.org/10.1002/anie.202007195}},
  doi          = {{10.1002/anie.202007195}},
  volume       = {{59}},
  year         = {{2020}},
}