The Surface Chemistry of Methanol on Cu3Pd(111): Effects of Metal Alloying and Reaction with Hydrogen

• DOI: 10.1021/acs.jpcc.4c07648
• Publication Date: 2025-01-24T19:56:17Z
• Authors: Kasala Prabhakar ...; Jeongjin Kim; Hojoon Lim; Arephin Islam; Irene Barba-Nieto; Xiao Tong; Adrian Hunt; Iradwikanari Waluyo; José A. Rodriguez

Synchrotron-based ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) was used to study the adsorption and surface chemistry of methanol on a Cu3Pd(111) model surface. The composition morphological properties pristine substrate were analyzed using combination low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), ion scattering (LEIS). results showed segregation Pd toward surface, with Pd/Cu ratio close 0.5, larger value than 0.33 expected for Cu3Pd bimetallic structure. alloy exhibited good LEED pattern 3-fold long-range periodicities. In STM, clusters palladium hexagonal arrays Pd–Pd distances 2.7–2.8 Å detected. Bonding copper perturbed electronic atoms in clusters, shifting their 4d states higher binding energy respect Fermi level. valence band spectrum line shape that very different from those displayed by Cu(111) or Pd(111). At low pressures, at 300 K mainly produced CH3O, CO, CHx species. AP-XPS most interacted decomposition products methanol. No significant changes observed core levels upon dissociation methanol, suggesting molecule sites alloy. Reaction hydrogen led fast removal CHx, C, PdCx species moderate (<450 K) temperatures prevented → C transformation. If stability adsorbed CH3O is as descriptor hydrogenation CO2 should be much better catalyst monometallic palladium. This may consequence ensemble effects reactivity sites.