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.