As a benchmark, we used a platinized Pt-poly disk (3 mm in diameter, Goodfellow Cambridge Limited, England, 99.9 %), prepared by potentiodynamic cycling of a smooth Pt-poly disk in H2PtCl6 solution, as described in ref. . Two Pt-poly electrodes were prepared with RF amounting to 5 and 20 (determined using HUPD peaks). HER/OER and HOR/ORR activities of Pt-poly electrodes were measured in the same way as for the Ni-poly and Rh-modified Ni-poly electrodes.