Methane Dehydrogenation on Rh@Cu(111): A First-Principles Study of a Model Catalyst

The issue of tuning the relative height of the first two dehydrogenation barriers of methane (CH4 → CH3 + H and CH3 → CH2 + H) is addressed using density-functional theory. It is shown that the combination of a very active reaction centersuch as Rhwith a more inert substratesuch as Cu(111)may hinder the second dehydrogenation step with respect to the first, thus resulting in the reverse of the natural order of the two barriers' heights.