The Difference Se Makes: A Bio-Inspired Dppf-Supported Nickel Selenolate Complex Boosts Dihydrogen Evolution with...

Area of Science:

• Inorganic Chemistry
• Electrochemistry
• Catalysis

Background:

• Hydrogenases are enzymes crucial for biological hydrogen production.
• Nickel-iron-selenium ([NiFeSe])-hydrogenases inspire the design of artificial catalysts.
• Developing efficient and stable molecular electrocatalysts for proton reduction is essential.

Purpose of the Study:

• To synthesize and evaluate a dppf-supported nickel(II) selenolate complex as an electrocatalyst for proton reduction.
• To investigate the role of selenium in the catalytic mechanism.
• To assess the oxygen and hydrogen tolerance of the nickel selenolate catalyst.

Main Methods:

• Electrochemical experiments were conducted to measure catalytic activity.
• Density Functional Theory (DFT) calculations were employed to elucidate the reaction mechanism.
• Comparison with a nickel thiolate analogue was performed.

Main Results:

• The nickel selenolate complex exhibited a high turnover frequency (TOF) of 7838 s^-1 for H₂ evolution, significantly outperforming the nickel thiolate analogue (600 s^-1).
• Selenium was identified as a key proton relay, enhancing catalytic activity.
• The catalyst demonstrated unprecedented tolerance to both oxygen and hydrogen.

Conclusions:

• Nickel selenolate complexes are highly efficient and stable electrocatalysts for proton reduction.
• The bio-inspired design incorporating selenium as a proton relay is effective.
• This work encourages the development of oxygen-tolerant molecular catalysts for hydrogen production.