Mitigating Cobalt Phthalocyanine Aggregation in Electrocatalyst Films through Codeposition with an Axially...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Cobalt phthalocyanine (CoPc) is a potential catalyst for aqueous carbon dioxide (CO2) electroreduction.
• Catalyst aggregation at high loadings limits CoPc's efficiency and stability.
• Dispersing CoPc is crucial for enhancing its catalytic activity and selectivity.

Purpose of the Study:

• To investigate the use of poly(4-vinylpyridine) (P4VP) as a dispersing agent for CoPc.
• To evaluate the impact of P4VP on CoPc aggregation and catalytic performance in CO2 electroreduction.
• To compare P4VP with other polymers like Nafion for CoPc dispersion and catalytic efficiency.

Main Methods:

• Codeposition of CoPc with P4VP onto carbon electrode surfaces.
• Characterization using transmission and diffuse reflectance UV-vis spectroscopy to study dispersion.
• Morphological analysis via Scanning Electron Microscopy (SEM).
• Electrochemical measurements to assess CO2 electroreduction activity and selectivity.

Main Results:

• P4VP effectively disperses CoPc in deposition solutions and prevents reaggregation in films through axial coordination and π-stacking.
• SEM images confirmed reduced aggregation and improved morphology of CoPc when codeposited with P4VP.
• CoPc codeposited with P4VP exhibited significantly higher CO2 electroreduction activity and selectivity compared to CoPc codeposited with Nafion.

Conclusions:

• P4VP is a superior dispersing agent for CoPc in CO2 electroreduction compared to Nafion.
• The enhanced dispersion by P4VP leads to improved catalytic activity and selectivity.
• This strategy offers a promising approach to optimize molecular catalysts for CO2 conversion.