@article{35381, author = {Alex J King and Justin C Bui and Alexis T Bell and Adam Z Weber}, title = {Establishing the Role of Operating Potential and Mass Transfer in Multicarbon Product Generation for Photoelectrochemical CO2}, abstract = {

There is increasing interest in the possibility of photoelectrochemical (PEC) reduction of CO2 to C2+ products; however, the criteria for maximizing PEC solar-to-C2+ (STC2+) rates are not well understood. We report here a continuum-scale model of PEC CO2 reduction (CO2R) on Cu in 0.1 M CsHCO3 and use it to optimize the design and operating conditions for generating C2+ products. We demonstrate that the potential-dependent product distribution of CO2R on Cu requires operating near the potential that maximizes C2+ generation rates (Vid), unlike PEC water splitting, which desires operation at the maximum photocurrent density. Because of this requirement, the criterion for a high STC2+ rate includes high-photocurrent semiconductors with photovoltages near Vid and low series resistance. The STC2+ rate in these systems is enhanced by optimal CO2 transport and exhibits low sensitivity to dirunal solar irradiance variations.

}, year = {2022}, journal = {ACS Energy Letters}, pages = {2694 - 2700}, month = {07/2022}, issn = {2380-8195}, url = {https://pubs.acs.org/doi/10.1021/acsenergylett.2c01041}, doi = {10.1021/acsenergylett.2c01041}, language = {eng}, }