Plasma-photocatalytic conversion of CO₂ at low temperatures: Understanding the synergistic effect of plasma-catalysis

Mei, Danhua; Zhu, Xinbo; Wu, Chunfei; Ashford, Bryony; Williams, Paul T.; Tu, Xin

Abstract

A coaxial dielectric barrier discharge (DBD) reactor has been developed for plasma-catalytic conversion of pure CO₂ into CO and O₂ at low temperatures (<150 °C) and atmospheric pressure. The effect of specific energy density (SED) on the performance of the plasma process has been investigated. In the absence of a catalyst in the plasma, the maximum conversion of CO₂ reaches 21.7 % at a SED of 80 kJ/L. The combination of plasma with BaTiO₃ and TiO₂ photocatalysts in the CO₂ DBD slightly increases the gas temperature of the plasma by 6-11 °C compared to the CO₂ discharge in the absence of a catalyst at a SED of 28 kJ/L. The synergistic effect from the combination of plasma with photocatalysts (BaTiO₃ and TiO₂) at low temperatures contributes to a significant enhancement of both CO₂ conversion and energy efficiency by up to 250%. The UV intensity generated by the CO₂ discharge is significantly lower than that emitted from UV lamps that are used to activate photocatalysts in conventional photocatalytic reactions, which suggests that the UV emissions generated by the CO₂ DBD only play a very minor role in the activation of the BaTiO₃ and TiO₂ catalysts in the plasma-photocatalytic conversion of CO₂. The synergy of plasma-catalysis for CO₂ conversion can be mainly attributed to the physical effect induced by the presence of catalyst pellets in the discharge and the dominant photocatalytic surface reaction driven by the plasma.

Citation

Mei, D., Zhu, X., Wu, C., Ashford, B., Williams, P. T., & Tu, X. (2016). Plasma-photocatalytic conversion of CO₂ at low temperatures: Understanding the synergistic effect of plasma-catalysis. Applied catalysis. B, Environmental, 182(March), 525-532. https://doi.org/10.1016/j.apcatb.2015.09.052

• Journal Article Type: Article
• Acceptance Date: Sep 28, 2015
• Online Publication Date: Oct 2, 2015
• Publication Date: 2016-03
• Deposit Date: Oct 30, 2015
• Publicly Available Date: Nov 23, 2017
• Journal: Applied catalysis B : environmental
• Print ISSN: 0926-3373
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 182
• Issue: March
• Pages: 525-532
• DOI: https://doi.org/10.1016/j.apcatb.2015.09.052
• Keywords: Plasma-catalysis; Dielectric barrier discharge; CO₂ conversion; Synergistic effect; Energy efficiency
• Public URL: https://hull-repository.worktribe.com/output/380635
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0926337315301788
• Additional Information: Authors' accepted manuscript of article published in: Applied catalysis B : environmental, 2016, v.182.