Proceedings of MATSUS Fall 2024 Conference (MATSUSFall24)
DOI: https://doi.org/10.29363/nanoge.matsusfall.2024.234
Publication date: 28th August 2024
Carbon monoxide is an important raw material for the synthesis of different bulk chemicals (e.g., phosgene and different products thereof). Considering that it can be a building block for the synthesis of virtually any organic compound, carbon monoxide might play an important role in the production of synthetic fuels and other typical petrochemical products. This can be achieved at high temperatures and pressure in the Fischer-Tropsch process, rendering this a widely investigated topic. As an alternative, electrochemical methods offer a way of forming different chemicals from carbon monoxide under considerably milder conditions.
In this study, we aimed to explore the effect of different experimental parameters on the rate and selectivity of the electrochemical reduction of CO (CORR), using cell components and catalysts available from commercial sources. Studying the reaction in different electrolyzers, we highlight the dual effect of the electrolyte solution that separates the membrane and the catalyst layer. On the one hand, it limits the product crossover to the anode, but on the other hand, gives ground to electrode flooding, hence also limiting the maximum achievable current density. The zero-gap electrolyzer structure is therefore most beneficial in terms of both achievable reaction rate and energy efficiency, but product accumulation in the anolyte is a hurdle to get over, as will be further discussed in my talk.
The phase boundary between the catalyst particles, the liquid phase, and the gas reactant can be engineered by using functional catalyst layer additives. In the second part of my talk the effect of the used gas diffusion layer, the catalyst layer composition, and the catalyst additive will be discussed. Various, systematically chosen polymeric materials were tested as catalyst binders to reveal any possible contribution of certain molecular motifs (e.g., functional groups, fluorinated backbone, etc.), present in the polymer additives. The electrochemical results are contrasted with the detailed physico-chemical characterization of the catalyst layers. Building on these optimization studies, experiments were also performed in a scaled-up electrolyzer stack (3×100 cm2 geometric area) to evaluate the possible industrial applicability of this process.