Role of doping concentration on the RWGS performance of Cu doped CeO₂ catalysts

The reverse water-gas shift (RWGS) reaction efficiently transforms CO₂ into CO at high temperatures, ensuring high CO selectivity while preventing the formation of methane as a byproduct. Nanocrystalline ceria-based materials are synthesised by using a modified co-precipitation method. This method utilizes the molecular water in the precursor materials to aid the hydroxylation process, which helps minimize the risk of agglomeration resulting from hydrogen bonding. The as prepared catalysts were calcined at high temperature to get the crystalline materials. The freshly synthesized and calcined catalysts were analysed using various characterisation techniques such as X-ray diffraction (XRD), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS). The results suggest that enhancing the copper concentration in Cu-doped CeO₂ significantly improves its catalytic activity at low and moderate temperatures. Among all the catalysts 25 mol % copper doped CeO₂ gives extraordinary activity for RWGS reaction having CO₂ conversion of ~ 50% at 800 ˚C.