Identifying a Real Catalyst of [NiFe]‐Hydrogenase Mimic for Exceptional H₂ Photogeneration

Abstract

Inspired by the natural [NiFe]‐H2ase, we designed mimic 1, (dppe)Ni(μ‐pdt)(μ‐Cl)Ru(CO)2Cl to realize effective H2 evolution under photocatalytic conditions. However, a new species 2 was captured in the course of photo‐, electro‐, and chemo‐ one‐electron reduction. Experimental studies of in situ IR spectroscopy, EPR, NMR, X‐ray absorption spectroscopy, and DFT calculations corroborated a dimeric structure of 2 as a closed‐shell, symmetric structure with a RuI center. The isolated dimer 2 showed the real catalytic role in photocatalysis with a benchmark turnover frequency (TOF) of 1936 h−1 for H2 evolution, while mimic 1 worked as a pre‐catalyst and evolved H2 only after being reduced to 2. The remarkably catalytic activity and unique dimer structure of 2 operated in photocatalysis unveiled a broad research prospect in hydrogenases mimics for advanced H2 evolution.

Cu5FeS4 quantum dots as a single-component photo-assisted electrocatalyst for efficient hydrogen evolution

“…[1][2][3][4][5] Along this line, photocatalysis and electrocatalysis from renewable energy have emerged as clean alternatives for H 2 production beyond the traditional fossil fuel-based methods. [6][7][8][9] However, the low conversion efficiency of photocatalysis and the high cost of electrocatalysis greatly limit their large-scale applications. [10][11][12] Therefore, the development of photo-and electroactive integration technologies has attracted great attention, such as photovoltaic-cell-driven electrocatalysis (PV-EC) and photoelectrochemical (PEC) strategies.…”

Electrocatalytic Hydrogen Evolution by Cobalt Complexes with a Redox Non-Innocent Polypyridine Ligand

“…3 Taking advantage of uniform and well-defined structures in solution, 3d transition metal complexes are ideal molecular models that provide mechanistic insights about HER occurring at the active metal sites of hydrogenases as well as heterogeneous single atomic catalysts. 4,5 Molecular cobalt complexes with various types of polypyridyl ligands have drawn great attention due to their high catalytic efficiency toward HER. 6−11 The polypyridyl ligand platform offers the resistance of the complexes against the acidic environment, which is inevitable for HER and, at the same time, stabilizes low-valent metal intermediates involved in the catalytic cycle.…”

“…In recent laboratory experiments, 3d transition-metal single atomic catalysts supported on nitrogen-rich carbon substrates have shown high efficiency toward the electrocatalytic hydrogen evolution reaction (HER) with small overpotentials . Taking advantage of uniform and well-defined structures in solution, 3d transition metal complexes are ideal molecular models that provide mechanistic insights about HER occurring at the active metal sites of hydrogenases as well as heterogeneous single atomic catalysts. , …”

Self-Assembled Nickel-4 Supramolecular Squares and Assays for HER Electrocatalysts Derived Therefrom

“…The so-called “sharp” currents are ascribed to a path for H 2 production within the nickel species, which was corroborated by gas chromatography after applying a constant potential at −1.60 V for 1 h (Figure S32). Such sharp responses are frequently observed in molecular catalysts for electrochemical H 2 production in water. − …”