Initial Application of Selected-Ion Flow-Tube Mass Spectrometry to Real-Time Product Detection in Electrochemical CO2 Reduction

Electrochemical CO2 reduction (EC-CO2R) has seen a resurgence in interest over the past several years; however, the means of analyzing catalytically produced products continues to rely on decades-old methods such as gas chromatography, high-performance liquid chromatography, and nuclear magnetic resonance. Real-time analysis of the gaseous and liquid products of this reaction is highly desirable; however, few analytical techniques have been developed thus far to meet this need. Here, we demonstrate the first use of selected-ion flow-tube mass spectrometry (SIFT-MS) as an analytical tool capable of measuring in real time both the gas-and liquid-phase products of EC-CO2R in aqueous solution. SIFT-MS uses well-understood ion-molecule reactions to enable the analysis of similar multicomponent mixtures by preventing substantial fragmentation of the analyte. We lay out the framework in which to evaluate the tool's capabilities and show that the C-1-C-3 hydrocarbon, alcohol, and aldehyde products of CO2R should be quantitatively detectable.