Issue 7, 2023

Continuous-flow reactor with superior production rate and stability for CO2 reduction using semiconductor photocatalysts

Abstract

Semiconductor photocatalyst approaches for solar CO2 reduction are attractive due to their simplicity but have lagged in efficiency compared to less-integrated photoelectrochemical (PEC) approaches and to electrolysis reactors. We identify poor mass transport and catalyst deactivation as key constraints. To address them, we have developed a continuous-flow photocatalytic reactor system allowing us to control the triple-phase interface on the photocatalyst surface using the liquid and reactant gas flow rates. With the goal of selectively producing CO, the reactor is optimized by controlling the pressure and flow rates of the reactant gas and electrolyte in contact with both sides with the intermediately placed catalyst. In comparison to batch reactors with an immobile photocatalyst bed and gas phase CO2 or CO2 purged water, 10–24 times higher production rates are achieved for photocatalysts such as TiO2, ZnO, C3N4, and CdS by simply changing to the designed flow-type photoreactor without any catalyst modification. In addition, CO selectivity (93.2%) and long-term stability (>780 min) using the designed reactor are significantly enhanced compared to using the batch reactors (71.7%, <180 min for reduced 50% activity). We propose that the enhanced mass transport on the photocatalyst surface accelerates the desorption of the initial photolysis product, CO, and prevents the poisoning effect from deactivating photocatalyst activity. This study has the potential to facilitate the utilization of semiconductor-based photocatalytic reactions for achieving superior performance wih gaseous reactants.

Graphical abstract: Continuous-flow reactor with superior production rate and stability for CO2 reduction using semiconductor photocatalysts

Supplementary files

Article information

Article type
Communication
Submitted
16 Feb 2023
Accepted
15 May 2023
First published
05 Jun 2023

Energy Environ. Sci., 2023,16, 2869-2878

Author version available

Continuous-flow reactor with superior production rate and stability for CO2 reduction using semiconductor photocatalysts

H. Jung, C. Kim, H. Yoo, J. You, J. S. Kim, A. Jamal, I. Gereige, J. W. Ager and H. Jung, Energy Environ. Sci., 2023, 16, 2869 DOI: 10.1039/D3EE00507K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements