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In this work, a Pt catalyst supported on an equimolar Al 2 O 3 –CeO 2 binary oxide (Pt–Al–Ce) was prepared and applied in photo-thermo-chemical dry reforming of methane (DRM) driven by concentrated solar irradiation. It was found that the Pt–Al–Ce catalyst showed good stability in DRM reactions and significant enhancements in H 2 and CO production rates compared with Pt/CeO 2 (Pt–Ce) and Pt/Al 2 O 3 (Pt–Al) catalysts. At a reaction temperature of 700 °C under 30-sun equivalent solar irradiation, the Pt–Al–Ce catalyst exhibits a stable DRM catalytic performance at a H 2 production rate of 657 mmol g −1 h −1 and a CO production rate of 666 mmol g −1 h −1 , with the H 2 /CO ratio almost equal to unity. These production rates and the H 2 /CO ratio were significantly higher than those obtained in the dark at the same temperature. The light irradiation was found to induce photocatalytic activities on Pt–Al–Ce and reduce the reaction activation energy. In situ diffuse reflectance infrared Fourier transform spectroscopy ( in situ DRIFTS) was applied to identify the active intermediates in the photo-thermo-chemical DRM process, which were bidentate/monodentate carbonate, absorbed CO on Pt, and formate.more »The benefits of the binary Al 2 O 3 –CeO 2 substrate could be ascribed to Al 2 O 3 promoting methane dissociation while CeO 2 stabilized and eliminated possible coke formation, leading to high catalytic DRM activity and stability.« less

CO2 reforming or dry reforming of methane (DRM) produces syngas with a low carbon footprint, but the efficiency and stability of DRM remains a challenge. Herein, we report an efficient photo-thermo-chemical DRM (PTC-DRM) process on a Pt supported CeO2 catalyst with Zn doping and surface atomic layer deposition (ALD)-enabled MgO overcoating using concentrated sunlight as the energy input. Under 30 suns irradiation at 600 °C, high syngas production rates of 356 and 516 mmol g−1 h−1 for H2 and CO are achieved, which are more than 9 and 3 times larger than those obtained in the thermally driven DRM. Moreover, the light illumination stabilizes the dry reforming process without deactivation, which results from the in situ generation of oxygen vacancy on CeO2 by photo-induced electrons that enables stable CO2 thermo-activation. The ALD coating also reduces surface charge recombination through passivating surface states, thereby enhancing photocatalytic activity.