Electrocatalytic hydrogen evolution by a dinuclear copper complex and mechanistic elucidation through DFT studies.

Area of Science:

• Inorganic Chemistry
• Electrochemistry
• Catalysis

Background:

• Dinuclear copper complexes are promising electrocatalysts.
• Electrochemical hydrogen evolution reaction (HER) is crucial for clean energy.
• Developing efficient catalysts for HER is an ongoing research area.

Purpose of the Study:

• To synthesize and characterize a novel dinuclear copper complex, [CuII2(L1)2].
• To investigate the catalytic activity of [CuII2(L1)2] for the electrochemical hydrogen evolution reaction (HER).
• To elucidate the mechanism of HER catalyzed by the copper complex.

Main Methods:

• Synthesis and spectroscopic characterization of the dinuclear copper complex.
• Electrochemical studies including redox potential measurements and catalytic activity assessment for HER.
• Gas chromatography for detection and quantification of evolved hydrogen.
• Density functional theory (DFT) calculations to study the reaction mechanism.

Main Results:

• The dinuclear copper complex [CuII2(L1)2] was successfully synthesized and characterized.
• The complex exhibited high catalytic activity for HER in DMF/H2O with acetic acid, achieving 93% faradaic efficiency at -1.9 V vs. SCE.
• Mechanistic studies revealed a concerted proton-coupled electron transfer (PCET) pathway involving a Cu-H bond intermediate with low activation energy.

Conclusions:

• The novel dinuclear copper complex [CuII2(L1)2] is an effective electrocatalyst for HER.
• The HER proceeds via a PCET mechanism facilitated by the copper complex.
• This study provides insights into the design of efficient copper-based electrocatalysts for hydrogen production.