Integrating photocatalysis and thermocatalysis to enable efficient CO2 reforming of methane on Pt supported CeO2 with Zn doping and atomic layer deposited MgO overcoating

[Display omitted] •Photo-thermo-chemical CO2 reforming of CH4 (PTC-DRM) developed by integrating photocatalytic and thermocatalytic effects.•PTC-DRM activity on Pt supported CeO2 promoted by Zn doping and atomic layer deposition (ALD) enabled MgO overcoating.•Zn doping and ALD overlayer prevent charge carrier recombination.•Light irradiation stabilizes DRM by balancing consumption and generation of oxygen vacancies as CO2 activation sites. 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.