Fully Integrated Stand-Alone Device for Gas-Phase CO2 Reduction Using Sunlight: Proof of Concept

Thursday, October 15, 2015: 11:30
104-B (Phoenix Convention Center)
M. Arab, T. L. Church, X. Li, T. Maschmeyer (The University of Sydney), and A. I. Minett (The University of Sydney)
The conversion of CO2 to fuels can be a promising pathway to reduce the carbon intensity of the economy, if the energy required for its conversion is supplied from renewable sources. We showcase a fully integrated, wireless, stand-alone unbiased photoelectrochemical cell (PEC) for the conversion of CO2 and H2O to chemicals and fuels in gas phase. Simulated sunlight at 1 Sun intensity is used to drive the conversion reaction. Proof-of-concept experiments show that the device is operational in dilute CO2 streams (10% CO2, 2% H2O, Ar balance) as well as in concentrated CO2 streams (98% CO2, 2% H2O). With a Cu sheet as the cathode catalyst, the device offers a CO2 reduction selectivity of ~50%; when Cu2O nanorods are employed, the selectivity toward CO2 reduction increases to ~90%. Experiments related to improving the performance of the device, testing other catalyst materials, and detecting the products is ongoing. The cell is lightweight, built of earth-abundant materials, and easy to assemble and scale. Further, it operates in dilute CO2 streams and the gas-phase operation facilitates the separation of liquid products. Thus the device represents a promising avenue toward the direct conversion of CO2 from flue gas or even air, without the need to first capture the CO2.

Figure 1- Chronoamperometry experiments when the device is under interval illumination with difference cathode materials; a) Cu2O Nanorods, b) Cu sheet.