2024/12/20 by Mitsunori Kurahashi
Energy · Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #CO oxidation #Catalytic Processes in Materials Science #Electrocatalysts for Energy Conversion #alignment #molecular oxygen #platinum #step
paper · pdf · doi:10.48505/nims.5191
openalex publication_date 2024/12/20 · openalex created_date 2025/12/07 · openalex updated_date 2026/08/01
Steric effects in O2 chemisorption and catalytic CO oxidation on stepped Pt(111) surfaces have been investigated by scanning a narrow alignment-controlled O2 beam across a curved Pt(111) surface, on which the densities of \100\ (A-type) and \111\ (B-type) steps vary smoothly with the distance from the center of the crystal. The contribution of trapping-mediated and activated chemisorption to these processes on the terraces and steps were discussed based on the dependence of these processes on the kinetic energy (80-500 meV) and alignment of O2. The results indicate that (i)the probability of activated O2 chemisorption on surfaces with type-B steps is slightly lower than that on surfaces with type-A steps, (ii) CO oxidation proceeds both at terraces and steps at the sample temperature of 693 K while it happens only at terraces at 423 K. The results of CO oxidation experiments at 423 K indicate that the rate of CO2 production at terraces of the stepped Pt(111) surface is lower than at a flat (111) surface and depends on the step structure.