"Here we find that Pt in a higher oxidation state (that is, PtO) demonstrates remarkable HOR suppression ability, while its hydrogen evolution capacity is still comparable to that of the benchmark of conventional metallic Pt cocatalyst through comprehensive experimental and theoretical analysis." Yu Hang Li et al. Unidirectional suppression of hydrogen oxidation on oxidized platinum clusters https://www.nature.com/articles/ncomms3500

That is, the catalyst (PtO) accelerates the forward reaction, 2H+ - H_2, but SUPPRESSES the reverse reaction, H_2 - 2H+. Violation of the second law of thermodynamics par excellence. The picture in the paper is more than convincing:

http://images.nature.com/m685/nature...mms3500-f1.jpg

Pentcho Valev