Highly Exposed NH₂ Edge on Fragmented g‐C₃N₄ Framework with Integrated Molybdenum Atoms for Catalytic CO₂ Cycloaddition: DFT and Techno‐Economic Assessment

Abstract

This study focuses on the applicability of single-atom Mo-doped graphitic carbon nitride (GCN) nanosheets which are specifically engineered with high surface area (exfoliated GCN), NH₂ rich edges, and maximum utilization of isolated atomic Mo for propylene carbonate (PC) production through CO₂ cycloaddition of propylene oxide (PO). Various operational parameters are optimized, for example, temperature (130 °C), pressure (20 bar), catalyst (Mo₂ GCN), and catalyst mass (0.1 g). Under optimal conditions, 2% Mo-doped GCN (Mo₂ GCN) has the highest catalytic performance, especially the turnover frequency (TOF) obtained, 36.4 h^-1 is higher than most reported studies. DFT simulations prove the catalytic performance of Mo₂ GCN significantly decreases the activation energy barrier for PO ring-opening from 50-60 to 4.903 kcal mol^-1 . Coexistence of Lewis acid/base group improves the CO₂ cycloaddition performance by the formation of coordination bond between electron-deficient Mo atom with O atom of PO, while NH₂ surface group disrupts the stability of CO₂ bond by donating electrons into its low-level empty orbital. Steady-state process simulation of the industrial-scale consumes 4.4 ton h^-1 of CO₂ with PC production of 10.2 ton h^-1 . Techno-economic assessment profit from Mo₂ GCN is estimated to be 60.39 million USD year^-1 at a catalyst loss rate of 0.01 wt% h^-1 .