This work describes the generation of highly reactive Lewis pair sites on CuMo-oxides for CO₂ activation and utilization over the cyclization reaction to produce propylene carbonate from 1,2-propanediol. The CuMo-oxides were synthesized by enabling the oxygen vacancies that enhance the catalytically active sites, resulting in the formation of metastable cations (Mo⁵⁺ and Cu⁺) and oxygen vacancies. Under ethanol-PEG-400 medium, the pure phase of Cu₃Mo₂O₉ obtained at 500 °C exposed maximum defects without any secondary phase compared to the other screened catalysts. The experimental and theoretical investigations provided evidence for determining and correlating the characteristics of active sites with catalytic performance. The catalysts were extensively characterized along with DFT studies, which revealed the presence of defect centers as one of the key factors in the enhanced activity. From the chemical bonding analysis, i.e., the Crystal Orbital Hamiltonian Population (COHP) and Electron Localization Function (ELF), the CO₂ molecule is known to form a strong chemisorption interaction with the catalyst surface that is facilitated by the oxygen vacancy/Lewis pairs. The Cu-Mo oxide catalyst exhibited a better performance under optimal reaction conditions with a 1,2-propanediol conversion of 99% and propylene carbonate yield of 97% compared to the reported catalysts due to its inherent physicochemical properties. Thus, Cu-Mo oxides were shown to be highly efficient catalysts with good recyclability for the 1,2-propanediol and CO₂ reaction.