Solar-driven photo-thermo-chemical dry reforming of methane (PTC-DRM) is an attractive approach to mitigate global warming issue due to the energy source being sustainable and it has demonstrated higher efficiency than thermocatalytic DRM. The study of contribution of photocatalysis in the PTC-DRM process at high temperatures is still incomplete. In this work, the photocatalytic effects in PTC-DRM process were systematically investigated on a photoactive CeO2 supported Pt catalyst (Pt/CeO2). The Pt/CeO2 catalyst produced CO and H2 at rates under light irradiation 2.0 and 2.9 times as much as those obtained in the dark at the same temperature 650 °C. With various long-wavelength-pass filters applied, it reveals that the contributions of photocatalysis effects are mainly from lights less than 435 nm in wavelength, coincident with the band gap energy of CeO2, while those longer than 435 nm merely provide heat to drive thermocatalysis. Mechanistic studies from in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and from materials characterizations before and after the PTC-DRM reaction suggest that photo-irradiation regenerates surface oxygen vacancies, thus boosting CO2 activation and promoting formate and carbonate intermediates dissociation and conversion to final products. Understanding photocatalytic effects in PTC-DRM from this work provided insights in designing high-performance catalysts for more efficient solar energy utilization.

Contribution of photocatalysis in solar-driven photo-thermo-chemical dry reforming of methane on a Pt/CeO2 catalyst

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.