Bis(cyclopentadienyl)nickel(II) μ-Thiolato Complexes as Proton Reduction Electrocatalysts

Area of Science:

• Inorganic Chemistry
• Electrochemistry
• Catalysis

Background:

• Proton reduction electrocatalysis is crucial for sustainable energy technologies.
• Developing efficient and robust catalysts is a key challenge.

Purpose of the Study:

• To synthesize and evaluate novel thiolato-bridged cyclopentadienylnickel dimeric complexes as proton reduction electrocatalysts.
• To investigate the catalytic activity and mechanism of these nickel complexes.

Main Methods:

• Cyclic voltammetry was employed to study the electrocatalytic activity.
• Acetic acid was used as the proton source.
• Electrochemical-chemical-electrochemical-chemical mechanism was proposed.

Main Results:

• The nickel complexes demonstrated efficient and robust proton reduction catalysis.
• Moderate overpotentials (~0.6 V) and high catalytic current ratios (7.8–12.2) were observed.
• A turnover number of approximately 7 was determined for each complex.
• The thiolato substituent did not significantly impact catalytic performance.

Conclusions:

• Thiolato-bridged cyclopentadienylnickel dimeric complexes are effective homogeneous electrocatalysts for proton reduction.
• These catalysts exhibit robustness and sustained activity over extended periods.
• The proposed mechanism provides insight into the catalytic process.