Experimental study on photothermocatalytic CO2 reforming of benzene

To improve the conversion efficiency and reduce the CO 2 emissions associated with the reforming of biomass tar to syngas, photothermal catalysts were prepared in this study through various impregnation methods. Photothermocatalytic CO 2 reforming (PTCR) of benzene as a tar model compound, was conducted using the prepared Ni/TiO 2 -Al 2 O 3 catalysts. The results show that the introduction of TiO 2 facilitates the conversion of NiO to Ni during the photothermal reaction, while the photocatalysis of TiO 2 significantly enhances the photothermocatalytic activity of the Ni/Al 2 O 3 catalysts at low temperatures. Moreover, the methodology for catalyst preparation involving the loading of NiO before TiO 2 is also beneficial to catalyst performance. However, when the mass ratio of TiO 2 to Al 2 O 3 exceeds 1, the specific surface area, pore volume, and structural stability of the catalysts are reduced. The results of PTCR experiment show the following optimal Ni/TiO 2 -Al 2 O 3 catalyst preparation parameters: 25% NiO content and a TiO 2 /Al 2 O 3 ratio of 3:7; 450 °C calcination temperature and a nitrogen atmosphere. The maximum benzene conversion achieved through PTCR with the 0.25Ni/0.3Ti0.7Al(M2) catalyst is 88.2%. However, a large amount of coke is deposited onto the spent catalyst surface, contributing significantly to catalyst deactivation.