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

Project Information

PoCalopH

Grant agreement ID: 101104814

DOI

10.3030/101104814

Project closed

EC signature date 19 July 2023

Start date 1 July 2024

End date 30 June 2026

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 203 464,32

Coordinated by

UNIVERSITEIT LEIDEN
Netherlands

Periodic Reporting for period 1 - PoCalopH (Polymer-Enhanced Electrocatalytic CO2 Reduction - The Influence of the Local pH Value)

Reporting period: 2024-07-01 to 2026-06-30

Summary of the context and overall objectives of the project

Converting carbon dioxide into valuable fuels through electrochemical reduction (CO2RR) is one approach to sustainable energy. However, current metal catalysts struggle with poor selectivity and energy efficiency. Recent advances have shown that polymer coatings can enhance catalyst performance, but these studies lack a clear understanding of the polymer’s role. Additionally, local pH fluctuations, which can impact catalytic activity, have never been systematically measured. Supported by the Marie Skłodowska-Curie Actions programme, the PoCalopH project will study how different polymer coatings influence CO2RR efficiency and selectivity on gold and copper catalysts. It will monitor pH changes in-situ. To close that knowledge gap, the role of polymer coatings on the electrochemical response of metal electrodes is systematically investigated (O1). To correlate the findings to in-polymer pH-values, fluorescent pH responsive polymers are prepared (O2) and local pH values are quantified under electrochemical conditions in-operando (O3). Finally, the gained insights are used to prepare porous polymer coated electrodes for high-current application (O4). This approach paves the way for the rational design of next-generation polymer-coated CO2RR catalysts.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

PocalopH identified that protic polymers like polyethylene imine and polyallyl amine modulate the electrochemistry of gold surfaces significantly, especially by accelerating the hydrogen evolution reaction.
Different pH detecting polymers were succesfully prepared and pH-read-out was realised in-operando by electrochemical confocal laser scanning microscopy.
This allowed to quantify the spatiotemporal pH distribution within the polymer during hydrogen evolution.
A finite-element model was applied to understand these results and pointed at a local buffering effect of the polymer-coating that in the future may be used to render electrochemical reactions more efficient.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Operando pH-readout under electrochemical conditions in polymer-coatings has been inaccessible at high spatial and temporal resolution before PocalopH.
Therefore, the project went significantly beyond the state of the art.

Although, local pH effects are often discussed in electrochemistry and electrocatalysis, they are seldomly assessed experimentally, especially in complex chemical environments.
Therfore, the developed methods has been used to understand the buffering properties of a polymer-coating. This pushed the border of what is known (and quantifyable) in complex reaction environments.

A physical model developed by a collaboration partner allows the community to simulate in-polymer pH values, now.

Being now established, the developed method opens a variety of new research pathways, including the investigation of the electrochemical CO2-reduction reaction, the embedding of molecular or biological catalysts in favorable environments, the investigation of aqueous batteries or porous model systems. Thus, the room for fundamental research on optimized polymer environments in electrochemistry is huge.

Although at low TRL currently, these fields have great promise of commercialisation and may benefit from the outcomes of PocalopH in the future.