A new catalyst, cerium phosphate (Ce(NO3)3/TSP), has been developed through a straightforward co-precipitation method. This catalyst was thoroughly characterized using techniques such as X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). The research focused on the application of Ce(NO3)3/TSP in the of 2,4,5-tri and 1,2,4,5-tetra substituted imidazole reaction with ammonium acetate, amine derivatives, benzil, and various aldehydes. The catalyst demonstrated outstanding performance, achieving product yields of 90-97% in just 8-10 minutes in an ethanol medium. The heterogeneity of the reaction was confirmed by a hot filtration test. This catalyst offers significant benefits, including easy recovery, reusability for at least five cycles, a simple work-up procedure, and high product yields. An evaluation of sustainability using green metrics such as the E-factor, atom economy (AE), reaction mass efficiency (RME), carbon efficiency (CE), and optimum efficiency (OE) indicated that this catalyst greatly enhances the environmental sustainability of the 2,4,5-tri and 1,2,4,5-tetra substituted imidazole reaction.