As anticipated from the hierarchical, and rough morphology of the catalyst surface, these electrocatalysts showed relatively similar electrocatalytic surface area (ECSA) which correlates to the double layer capacitance (Cdl) values of CoxB-[0.2]P-O (3.5 mF cm -2 ), CoxB-O (3.1 mF cm -2 ) and Co(OH)2 (2.6 mF cm -2 ) (Fig. F, Fig. ). While the ECSA values of the three materials are similar, the TOF measurements provide evidence that the local chemistry of the active site plays a more significant role in promoting the electrocatalytic efficiency of these catalysts. The strong anchorage of the catalyst even after the stability test on the highly porous and conductive 3D metal substrates provides a major advantage in contrast to conventional dropcasted coatings.