The implementation of hydrogen as a sustainable energy vector relies on the efficient production and oxidation of H2 at low cost using electrolysers and fuel cells, respectively.[1] The hydrogen oxidation reaction (HOR) at the anode of state-of-the-art fuel cell is performed by catalysts based on rare and expensive platinum metal, making these fuel cells less suitable for industrial applications.[2] Hydrogenases (H2ase) enzymes are the only known catalysts able to compete with Pt for the HOR with turnover frequencies up to 10000 s-1 thanks to the complex environment of the active site.[3] These H2ases are also known for their sensitivity to a large number of inhibitors such as CO, H2S and O2 and can show limited stability over time. In order to carry out H2 oxidation there are only a few examples of molecular catalysts able to perform this reaction near the thermodynamic potential with high turnover frequencies. They all belong to the family of Ni-based diphosphine complexes bearing integrated proton relays (Ni(P2N2)2), originally developed by the group of D. L. DuBois.[4] These bio-inspired catalysts have been immobilized onto carbon electrode surfaces and showed efficient H2 production and oxidation properties under acidic aqueous conditions.[5,6] More recently, the modification of the outer coordination sphere of these Ni based catalysts with arginine (Ni(P2NArg2)2) moieties showed drastic improvement in the electrocatalytic HOR performance in homogeneous conditions. The immobilization of this catalyst onto a carbon nanotube modified electrode gave rise to high current densities for HOR, up to 20 mA cm-2.[7] We will show how the elaboration of porous nano-structures led to further increased performance of the molecular based anode. The research leading to these results has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking under grant agreement No 779366. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme, Hydrogen Europe and Hydrogen Europe research. [1] N. Armaroli, V. Balzani, ChemSusChem 2011, 4, 21–36. [2] R. B. Gordon, M. Bertram, T. E. Graedel, Proc. Natl. Acad. Sci. 2006, 103, 1209–1214. [3] W. Lubitz, H. Ogata, O. Rüdiger, E. Reijerse, Chem. Rev. 2014, 114, 4081–4148. [4] A. D. Wilson, R. H. Newell, M. J. McNevin, J. T. Muckerman, M. Rakowski DuBois, D. L. DuBois, J. Am. Chem. Soc. 2006, 128, 358–366. [5] A. L. Goff, V. Artero, B. Jousselme, P. D. Tran, N. Guillet, R. Métayé, A. Fihri, S. Palacin, M. Fontecave, Science 2009, 326, 1384–1387. [6] T. N. Huan, R. T. Jane, A. Benayad, L. Guetaz, P. D. Tran, V. Artero, Energy Environ. Sci. 2016, 9, 940–947. [7] S. Gentil, N. Lalaoui, A. Dutta, Y. Nedellec, S. Cosnier, W. J. Shaw, V. Artero, A. Le Goff, Angew. Chem. Int. Ed. 2017, 56, 1845–1849.