Polyoxometalate-based electron transfer modulation for efficient electrocatalytic carbon dioxide reduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrocatalytic carbon dioxide reduction (CO2RR) suffers from poor selectivity due to complex electron transfer pathways.
• Polyoxometalates (POMs) offer tunable electron storage and release, acting as potential electronic regulators.
• Developing efficient CO2RR electrocatalysts is crucial for future energy solutions.

Purpose of the Study:

• To design and synthesize novel POM-based manganese-carbonyl (MnL) composite electrocatalysts for CO2RR.
• To investigate the role of POMs in modulating electron transfer for enhanced CO2RR activity and selectivity.
• To improve the efficiency and selectivity of CO2 reduction to carbon monoxide (CO).

Main Methods:

• Synthesis of POM-based MnL composite electrocatalysts.
• Electrochemical characterization, including cyclic voltammetry and chronoamperometry.
• Spectroscopic analyses: photoluminescence (PL) and transient photovoltage (TPV).
• Computational modeling using density functional theory (DFT).

Main Results:

• SiW12-MnL composite demonstrated superior CO2RR activity and selectivity for CO production.
• Faradaic efficiency (FE) for CO2RR to CO increased from 65% to a record 95% in aqueous electrolyte.
• POMs were identified as electronic regulators, controlling electron transfer and suppressing the hydrogen evolution reaction (HER).

Conclusions:

• POMs effectively modulate electron transfer in CO2RR electrocatalysts.
• The developed POM-MnL catalysts significantly enhance selectivity towards CO production.
• This work provides a new strategy for designing efficient electrocatalysts for CO2 reduction.