Noncovalent Integration of a Bioinspired Ni Catalyst to Graphene Acid for Reversible Electrocatalytic Hydrogen Oxidation.

Bertrand Reuillard (1) , Matías Blanco (2) , Laura Calvillo (2) , Nathan Coutard (1) , Ahmed Ghedjatti (1) , Pascale Chenevier (3) , Stefano Agnoli (2) , Michal Otyepka (4) , Gaetano Granozzi (3) , Vincent Artero (1)

1 SolHyCat - Solar fuels, hydrogen and catalysis
2 Dipartimento di Scienze Chimiche [Padova]
3 STEP - Synthèse, Structure et Propriétés de Matériaux Fonctionnels
4 Palacky University Olomouc

Efficient heterogeneous catalysis of hydrogen oxidation reaction (HOR) by platinum group metal (PGM)-free catalysts in proton-exchange membrane (PEM) fuel cells represents a significant challenge toward the development of a sustainable hydrogen economy. Here, we show that graphene acid (GA) can be used as an electrode scaffold for the noncovalent immobilization of a bioinspired nickel bis-diphosphine HOR catalyst. The highly functionalized structure of this material and optimization of the electrode-catalyst assembly sets new benchmark electrocatalytic performances for heterogeneous molecular HOR, with current densities above 30 mA cm-2 at 0.4 V versus reversible hydrogen electrode in acidic aqueous conditions and at room temperature. This study also shows the great potential of GA for catalyst loading improvement and porosity management within nanostructured electrodes toward achieving high current densities with a noble-metal free molecular catalyst.

Mots clés: molecular HOR; PGM-free fuel cells; molecular electrocatalysis; non-covalent catalyst immobilization; graphenic acid; bio-inspired catalysis

Domaines: Catalyse; Matériaux

Bertrand Reuillard, Matías Blanco, Laura Calvillo, Nathan Coutard, Ahmed Ghedjatti, et al.. Noncovalent Integration of a Bioinspired Ni Catalyst to Graphene Acid for Reversible Electrocatalytic Hydrogen Oxidation.. ACS Applied Materials & Interfaces, 2020, 12 (5), pp.5805-5811. ⟨10.1021/acsami.9b18922⟩. ⟨hal-02468287⟩