Deciphering Electrocatalytic Hydrogen Production in Water Through a Bioinspired Water‐Stable Copper(II) Complex Adorned with (N <sub>2</sub> S <sub>2</sub> )‐Donor Sites
Sangharaj Diyali, Subhajit Saha, Nilankar Diyali, Avantika Bhattacharjee, Abhishek Mallick, Suraj Kumar Agrawalla, Chandra Shekhar Purohit, Bhaskar Biswas
Abstract
Abstract Electrocatalytic hydrogen production stands as a pivotal cornerstone in ushering the revolutionary era of the hydrogen economy. With a keen focus on emulating the significance of hydrogenase‐like active sites in sustainable H 2 generation, a meticulously designed and water‐stable copper(II) complex, [Cl−Cu−L N2S2 ]ClO 4 , featuring the N,S‐type ligand, L N2S2 (2,2′‐((butane‐2,3‐diylbis(sulfanediyl))bis(methylene))dipyridine), has been crafted and assessed for its prowess in electrocatalytic H 2 production in water, leveraging acetic acid as a proton source. The molecular catalyst, adopting a square pyramidal coordination geometry, undergoes ‐Cl substitution by H 2 O during electrochemical conditions yielding [H 2 O−Cu−L N2S2 ] 2+ as the true catalyst, showcases outstanding activity in electrochemical proton reduction in acidic water, achieving an impressive rate of 241.75 s −1 for hydrogen generation. Controlled potential electrolysis at −1.2 V vs. Ag/AgCl for 1.6 h reveals a high turnover number of 73.06 with a commendable Faradic efficiency of 94.2 %. A comprehensive analysis encompassing electrochemical, spectroscopic, and analytical methods reveals an insignificant degradation of the molecular catalyst. However, the post‐CPE electrocatalyst, present in the solution domain, signifies the coveted stability and effective activity under the specified electrochemical conditions. The synergy of electrochemical, spectroscopic, and computational studies endorses the proton‐electron coupling mediated catalytic pathways, affirming the viability of sustainable hydrogen production.