Fig. 5: HER activities of alloy catalysts.

Total number of active sites counted in different ranges of |ΔGH| values as a function of various compositions for (a) Cu55-nCon, (b) Cu55-nNin, (c) Cu55-nRun, and (d) Cu55-nRhn alloy clusters. The dark green, green, and light green colors indicate the total number of active sites with the |ΔGH| values in the range of [0.0, 0.1), [0.1, 0.2), [0.2, 0.3), respectively.