Non-Zero Binding Enhances Kinetics of Catalysis: Machine Learning Analysis on the Experimental Hydrogen Binding Energy of Platinum

A thermoneutral
binding energy has been considered to yield maximum
catalytic activity for decades. However, recent theoretical studies
have challenged this criteria, because thermoneutrality only maximizes
the activity near equilibrium. Here, we report the experimental hydrogen
binding energy of platinum to be +0.094 eV, obtained by fitting microkinetic
rate equations to the Tafel plot. Upon increasing the overpotential,
the positive binding energy of platinum yields higher activity compared
to a thermoneutral catalyst. The trade-off between activity near equilibrium
and away from equilibrium suggests that thermoneutrality may not be
the ideal direction of catalyst design as traditionally considered.