Moiré-Induced Enhanced Hydrogen Adsorption on Graphene

The periodic patterning induced by moir & eacute; superstructures enables the synthesis of spatially functionalized graphene surfaces owing to changes in the local reactivity of the material. However, quantitative characterization of the effect of different moir & eacute; patterns remains elusive. By exploiting the large number of moir & eacute; superstructures appearing on epitaxial graphene grown on a Pt(111) surface, this stud examines the effect of moir & eacute;-induced corrugation on the local reactivity toward hydrogenation. This work combines atomically resolved scanning tunneling microscopy alongside density functional theory and Monte Carlo simulations of hydrogen chemisorption. The findings reveal a more efficient hydrogen adsorption onto moir & eacute; patterns compared to flat graphene, with a marked selectivity toward the most topographically protruding areas of the moir & eacute;. This moir & eacute;-induced enhancement of the hydrogenation efficiency is slightly increased on the most corrugated structures, which also display longer residence times and a higher stability against thermal desorption.