(707f) Optimizing Operating Conditions for Solar Driven CO2 Reduction Using High Performance GaAs and Silicon-Based Photocathodes
AIChE Annual Meeting
Friday, November 18, 2022 - 2:00pm to 2:18pm
We conducted an analysis of the photovoltaic (PV) behavior of the photocathodes and compared this to their photoelectrochemical behavior under solar-driven conditions. This photoelectrochemical behavior was also compared to the electrochemical behavior of the catalyst layer to evaluate the solar-driven system for any unique photo-effect, outside of the light absorption of the PV, which could enable improved I-V behavior with respect to a purely electrochemical system, or a âPV + electrolyzerâ architecture. To achieve this, we tested I-V points in both the light-limited and reaction-kinetics limited regions of the photoelectrochemical curve and compared their CO2R behavior to equivalent current points on the electrochemical I-V curve.
Finally, we modeled the diurnal output of an integrated solar-driven CO2R system by compiling data points collected at different light intensities to inform the conditions that must be controlled to maximize C2+ product selectivity over the course of a day. This model can be used to identify âtargetâ operating conditions (i.e., high voltage, low current vs. low voltage, high current) for solar-driven CO2R systems operating under ârealâ conditions.