Approaching Industrially Relevant Current Densities for Hydrogen Oxidation with a Bioinspired Molecular Catalytic Material

Integration of efficient platinum-group-metal (PGM)-free catalysts to fuel cells and electrolyzers is a prerequisite to their large-scale deployment. Here, we describe the development of a molecular-based anode for the hydrogen oxidation reaction (HOR) through noncovalent integration of a DuBois type Ni bioinspired molecular catalyst at the surface of a carbon nanotube modified gas diffusion layer. This mild immobilization strategy enabled us to gain high control over the loading in catalytic sites. Additionally, through the adjustment of the hydration level of the active layer, a new record current density of 214 +/- 20 mA cm(-2) could be reached at 0.4 V vs RHE with the PGM-free anode, at 25 degrees C. Near industrially relevant current densities were obtained at 55 degrees C with 150 +/- 20 and 395 +/- 30 mA cm(-2) at 0.1 and 0.4 V overpotentials, respectively. These results further demonstrate the relevance of such molecular approaches for the development of electrocatalytic platforms for energy conversion.

Automated summary

Integration of a DuBois type Ni bioinspired molecular catalyst onto the surface of a carbon nanotube modified gas diffusion layer through noncovalent binding allowed for precise control over catalytic site loading. By adjusting the hydration level of the active layer, record current densities were achieved with the PGM-free anode at different temperatures. These results highlight the relevance of molecular approaches in developing electrocatalytic platforms for energy conversion.