Solar-Driven Reduction of 1 atm CO_2 to Formate at 10% Energy-Conversion Efficiency by Use of a TiO_2-Protected III-V Tandem Photoanode in Conjunction with a Bipolar Membrane and a Pd/C Cathode Electrocatalyst
Abstract
A solar-driven CO_2-reduction (CO2R) cell, consisting of a tandem GaAs/InGaP/TiO_2/Ni photoanode in 1.0 M KOH(aq) (pH=13.7) to facilitate the oxygen-evolution reaction (OER), a Pd/C nanoparticle-coated Ti mesh cathode in 2.8 M KHCO_3(aq) (pH=8.0) to perform the CO_2R reaction, and a bipolar membrane to allow for steady-state operation of the catholyte and anolyte at different bulk pH values, was constructed. At the operational current density of 8.5 mA cm^(-2), in 2.8 M KHCO_3(aq), the cathode exhibited <100 mV overpotential and >94% Faradaic efficiency for the reduction of 1 atm of CO_2(g)to formate. The anode exhibited 320 ± 7 mV overpotential for the OER in 1.0 M KOH(aq), and the bipolar membrane exhibited ~480 mV voltage loss with minimal product crossover as well as >90% and >95% selectivity for protons and hydroxide ions, respectively. The solar-driven CO_2R cell converted sunlight to fuels at an energy-conversion efficiency of ~10%.
Additional Information
© 2017 ECS - The Electrochemical Society. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993. S.A.F. acknowledges the Resnick Sustainability Institute at Caltech for a Postdoctoral Fellowship. The authors also thank N. Dalleska (Caltech) for his assistance with measurements and analysis of the ICPMS and TIC data.Additional details
- Alternative title
- Solar-Driven Reduction of 1 atm CO2 to Formate at 10% Energy-Conversion Efficiency by Use of a TiO2-Protected III-V Tandem Photoanode in Conjunction with a Bipolar Membrane and a Pd/C Cathode Electrocatalyst
- Eprint ID
- 89638
- Resolver ID
- CaltechAUTHORS:20180914-100811320
- DE-SC0004993
- Department of Energy (DOE)
- Resnick Sustainability Institute
- Created
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2018-09-14Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- JCAP, Resnick Sustainability Institute