DYNACAT: DYNAmic phase formations and evolutions of the electroCATalysts for enhanced carbon capture and conversion

The climate change and energy crises are two of the most pressing problems now facing humanity. To mitigate these matters, it is imperative to find ways to reduce CO2 in the atmosphere and to reduce the usage of fossil fuels by replacing them with green energy. The electrochemical reduction of CO2 (CO2RR) is an emerging methodology in which CO2 is used to produce valuable multi-carbon chemicals and fuels, and therefore address both CO2 emissions and energy crises. This electrochemical process can only be efficient if high-activity electrocatalysts are used to promote the reduction reaction, and the properties of these catalysts are highly dependent on the morphology, shape and structure of the used materials. It is of utmost importance to understand the relation between structure-property and efficiency of these catalyst by proper characterization tools. The true nature of reactions can only be unveiled if they are studied in real or close-to-real conditions, i.e. in-situ characterization methods. In-situ electrochemical liquid cell transmission electron microscopy (EC-LC TEM) is a highly promising technique emerging to provide a reasonable correlation between phase formation and evolution with regard to the electrochemical activity, while observing real-time processes in a liquid environment with unprecedented spatial, temporal and energy resolutions. With this state-of-the-art technique, not only the morphology, but also structure, chemical composition, and electronic structure evolutions can be detected and measured, while simultaneously recording the electrochemical signature. Using electrodeposition process, it is possible to directly synthesize the studied materials in the liquid cell with control of desired shape/structure for higher efficiency of relevant catalytic reactions, in correlation to electrochemical signatures. The as-synthesized structures may be further analyzed for their catalytic properties. In this project, the electrodeposition and electrocatalytic performance analysis of copper and gold for designing high-efficiency electrocatalysts for CO2RR is proposed. The in-situ electrochemical liquid cell TEM technique will be used to study the processes under real reaction conditions using a liquid electrolyte, while monitoring the phase formation and evolution in real time. By correlating the shape/structure of the Cu and Au deposits to the electrochemical signatures, a fundamental understanding of the catalyst phase formation and growth will be achieved. Furthermore, the as-synthesized Cu and Au structures will be exposed to CO2-saurated electrolytes in reducing conditions, and their evolution during the catalysis reaction will be monitored and correlated to electrochemical properties. An established radiolysis model will be adapted for the conditions used in these experiments for reliable interpretation of the observed phenomena under the high-energy electron beam. Ex-situ TEM experiments will be conducted prior to in-situ experiments to determine appropriate process parameters for in-situ experiments, and to generate comparative benchmarks for microscopic observations. The correlation of in-situ and ex-situ results with regards to the radiolysis modelling will be used to gain an understanding of catalytic particles phase formation. The as-synthesized structures will be further exposed to the CO2-saturated solutions and their evolutions under such conditions will be evaluated. The obtained experimental results based on catalyst morphology-structure-property relationships will form the fundaments to formulate and design catalysts with increased activity/selectivity/stability for high-yield CO2 conversion reactions into value-added multicarbon products and fuels, opening the way for radically less CO2 entering the atmosphere while creating new markets for CO2 derived products.