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Updated: Sep 1, 2025
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Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of ChalcogenidoplumbatesII or IV
Published on: December 29, 2016
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Structure Matters: Asymmetric CO Oxidation at Rh Steps with Different Atomic Packing.
Fernando García-Martínez1, Lisa Rämisch2, Khadiza Ali3
1Departamento Física Aplicada, Universidad del País Vasco, San Sebastián 20018, Spain.
Journal of the American Chemical Society
|August 12, 2022
Summary
This study reveals that triangular B-type steps on rhodium catalysts are more efficient for carbon monoxide (CO) oxidation than square A-type steps. B-steps ignite at lower temperatures and maintain higher activity during the catalytic reaction.
Area of Science:
- Surface Science
- Catalysis
- Materials Science
Background:
- Curved crystals enable detailed study of step sites in heterogeneous catalysis.
- Understanding the role of atomic step geometry is crucial for designing efficient catalysts.
Purpose of the Study:
- To investigate the impact of A-type (square) and B-type (triangular) step atomic packing on catalytic CO oxidation on Rh(111) at millibar pressures.
- To elucidate the differences in reaction initiation and active species between A- and B-type steps.
Main Methods:
- Utilized a curved Rh(111) crystal to study step site effects.
- Employed laser-induced CO2 fluorescence imaging for reaction ignition monitoring.
- Conducted ambient pressure X-ray photoemission (AP-XPS) to analyze surface species and structure.
Main Results:
- B-type steps exhibit lower ignition temperatures compared to A-type steps.
- AP-XPS revealed distinct surface behaviors: CO desorption and oxygen buildup at B-steps, and O-Rh-O trilayer formation at A-steps.
- Chemisorbed oxygen dominates at B-steps, indicating higher activity.
Conclusions:
- B-type steps are significantly more efficient catalysts for CO oxidation than A-type steps.
- The atomic geometry of step sites profoundly influences catalytic performance and reaction mechanisms.
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