CO2 hydrogenation over acid-activated Attapulgite/Ce0.75Zr0.25O2 nanocomposite supported Cu-ZnO based catalysts

A series of Cu-ZnO based catalysts supported on the Attapulgite/Ce0.75Zr0.25O2 (ATP-CZO) nanocomposite prepared by different methods were synthesized using impregnation method for CO2 hydrogenation to CO and methanol. The physicochemical properties and catalytic performance of these catalysts were investigated by N-2 adsorption/desorption, XRD, FE-SEM, TEM, N2O chemisorption, XPS, H-2-TPR and CO2-TPD techniques. Results showed that the ATP-CZO-SC-P400 nanocomposite prepared by polyethylene glycol (PEG 400) modified solution combustion (SC) method owned the best dispersion of CZO particles on the ATP-CZO composite. Due to the dispersing effect of PEG 400, the intensity of Ce0.75Zr0.25O2 solid solution was enhanced, and the interaction between Ce-Zr-O oxides and ATP support was improved. Furthermore, the formation of strong basic sites and copper surface area of the catalyst were enhanced. As a result, the CZFK/ATP-CZO-SC-P400 catalyst showed the highest yield of methanol and CO from CO2 hydrogenation. The intimate contact between metallic Cu sites and strong basic sites of ZnO, ATP-CZO composite and ZnO-CZO interfaces on the surface of catalyst was considered as an important factor. Attapulgite, with unique property, low cost and easy availability, is a potential catalyst support for CO2 hydrogenation reaction.