pubs.acs.org/JPCL
A New Solar Carbon Capture Process: Solar Thermal Electrochemical Photo (STEP) Carbon Capture )
Stuart Licht,*,†,§ Baohui Wang,†,§, Susanta Ghosh,†,§,z Hina Ayub,†,§ Dianlu Jiang,†,§ and Jason Ganley‡,§ †
Department of Chemistry and Solar Institute, George Washington University, Washington, DC 20052, and Department of Chemical Engineering, Howard University, Washington, DC 20059
‡
ABSTRACT The first experimental evidence of a new solar process, combining electronic and chemical pathways, to isolate CO2 (carbon capture) is presented. This solar thermal electrochemical photo (STEP) process is a synergy of solid-state and solar thermal processes, and is fundamentally capable of converting more solar energy than photovoltaic or solar thermal processes alone. Here, CO2 is captured using a 750-950 °C electrolysis cell powered by a full spectrum solar simulator in a single step. The process uses the full spectrum; solar thermal energy decreases the energy required for carbon capture, while visible sunlight generates electronic charge to drive the electrolysis. CO2 can be captured from 34% to over 50% solar energy efficiency (depending on the level of solar heat inclusion), as solid carbon and stored, or used as carbon monoxide to be available for a feedstock to synthesize (with STEP generated hydrogen) solar diesel fuel, synthetic jet fuel, or chemical production. SECTION Energy Conversion and Storage
less than ∼900 °C in the molten electrolyte, solid carbon is the preferred CO2 splitting product, while carbon monoxide is the preferred product at higher temperature. As seen in the main portion of the figure, the electrolysis potential is
