Given that society will always need carbon based products such as plastics, nylons and organic solvents and probably high density fuels for aviation and shipping, this entails there is an urgent need to produce carbon based products sustainably. CO2 electrolysis to building-block chemicals such as CO, ethanol, and ethylene shows great promise, however there is still substantial development and understanding needed to operate at industrially relevant current densities (>100 mA/cm2) and maintaining stable performance for 1000s of hours.

This talk will focus on using in synchrotron based x-rays to analyze a zero-gap membrane electrode CO2 electrolysis device in operando. Not only does x-ray diffraction allow us to see changing oxidation state of our copper catalyst, but we can also see the Bragg peaks of any formation of salt precipitations in-situ, which is a substantial issue in these devices since they block mass transfer. Furthermore by analyzing background scattering, we can also visualize electrolyte variations within our cathodic gas diffusion layer. By having our in-operando device attached to both an in-line gas chromatograph and mass spectrometer we can relate product variations to variation in parameters visualized via the x-ray analysis and thus have a more comprehensive understanding of our devices. In this talk, we will discuss how variations in both anode electrolyte concentration and type (e.g. Li, Cs) have a substantial impact in both electrolyte penetration into the cathodic gas diffusion layer as well as how and where these salts may precipitate out and cause mass transfer issues.