Subtle and reversible interactions of ambient pressure H2 with Pt/Cu(111) single-atom alloy surfaces

摘要: Abstract Pt-Cu single-atom alloys (SAA) have been identified as promising hydrogenation catalysts with an ability to activate H2 better than the individual metals alone. We studied interaction between and Pt/Cu(111) SAA model surface using ambient pressure X-ray photoelectron spectroscopy (AP-XPS). A binding energy shift in Pt 4f spectrum indicates presence of adsorbed H at 350 K, occurring because bond activation. No evidence was found either segregation, subsurface diffusion atoms, or any effects on thermal stability surface, likely due subtle H. This is reversible upon evacuation H2, which a sign weak interaction. In addition, we effect CO co-adsorption that while unaffected by poisoning small amount can displace almost half sites 300 K. The susceptibility increases after heated 450 K changes structure layer enhance sites.