Polymer-Enhanced Electrocatalytic CO2 Reduction - The Influence of the Local pH Value

The electrochemical CO2 reduction reaction (CO2RR) has the unique potential to utilize the vast carbon source CO2 for production of valuable synthetic fuels being a sustainable process, if the electricity is obtained from renewable energy sources. Several metal surfaces are known to catalyze the electrochemical CO2RR.

However, they suffer from poor selectivity and energy efficiency. Recently, this limitation has been mitigated by functionalizing metal catalysts with polymer-coatings. However, previous investigations are non-systematic.

Several electrocatalysts (Au, Cu, Ag, Pt) of different morphologies (bulk electrodes, nanoparticles, foams) were combined with a variety of different polymers. This renders a general view of the polymers role in electrocatalysis impossible.

Coordinative stabilization of intermediates is the most frequently proposed origin of the performance increase, however, local effects like pH fluctuations were never detected. This is a severe gap of knowledge considering the high pH sensitivity of electrocatalysts.

Within PoCalopH, the researcher will, therefore, systematically investigate the influence of various polymer-coatings on the selectivity and efficiency of gold and copper catalysts and will correlate these effects to local pH changes.

This will be realized by equipping the most efficient polymers with fluorescent pH reporters allowing for a spectroscopic pH read out. The results will be systematically compared to those obtained from non-coated electrodes.

Therefore, PoCalopH will create a double benefit of polymer-coatings combining performance increase with valuable insights into local pH-effects within the coating.

This will precise mechanistic knowledge on the electrochemical CO2RR and may enable the rational design of polymer-coated CO2RR catalysts.