Introduction to the Principles of Electrochemistry through an Affordable Hands-on Electrochemical CO2 Reduction Experiment

Abstract

We are grateful for the invitation to this session by Prof. Alice H. Suroviec. Electrochemical conversion of CO2 to useful chemicals and synthetic electrochemistry in general are rapidly developing and expanding areas of research and industrial application, which necessitates developing undergraduate curricula that will help students build and retain a strong foundational knowledge in this area of chemistry. Currently, there is a limited set of electrochemistry experiments that undergraduate students are typically exposed to in the laboratory, and synthetic electrochemistry is generally limited to water electroreduction to generate hydrogen gas. As a result, students develop limited knowledge, interest and appreciation of synthetic electrochemistry. At the same time, students today are more inclined to learn about methods and concepts that are important for climate action and sustainable development. With this motivation in mind, we developed a laboratory experiment designed to actively engage students in the learning process and help them understand synthetic electrochemistry through a hands-on experience involving CO2 electroreduction. In general, CO2 electroreduction can yield many different chemicals and requires complex and expensive electrochemical workstation and analytical instrumentation to identify and quantify the products, making it prohibitive for wide adaptation in undergraduate laboratories. Here, we propose a simple and affordable setup that still allows students to directly experience all the necessary steps of the process. The proposed laboratory experiment involves testing the performance of different cathodic electrocatalysts in CO2 reduction reaction conducted in a DIY divided electrochemical cell by measuring the produced CO gas with a CO meter using affordable and broadly available supplies. The students learn the importance of the electrocatalyst composition by changing the material of the cathode and observing different amounts of CO produced or the absence of CO when using the electrode selective for only water reduction. They learn about the influence of the applied potential on the reaction rate by changing the battery voltage and observing the quantitative difference in the produced gas. The experiment is designed to be safe when conducted on a standard laboratory bench (i.e., carbon monoxide concentrations outside of the cell are below the threshold of a standard CO detector).