Mingled Metal Oxides Catalyst for Direct Carbonylation of Glycerol into Glycerol Carbonate

The escalation of CO2 into the atmosphere has encouraged the development of sustainable pathways to produce materials and chemicals from CO2. In the present manuscript, an attempt has been made for direct carbonylation of glycerol into Glycerol carbonate (GC) by using CO2 over mingled metal oxide (MMO) catalyst. Several single, bi and trimetal oxides catalysts were explored for direct carbonylation of glycerol. Among the tested catalysts, Cu incorporated MMO showed the profound effect to obtain maximum glycerol conversion and GC selectively. However, a series of MMO catalysts with variable Cu loading were synthesized by simple co-precipitation method and tested for direct carbonylation of glycerol. Of all tested Cu loaded MMO catalyst, 5 % Cu loaded MMO catalyst (CuO/CeO2/ZnO) showed highest GC selectivity (99 %). Furthermore, the process intensification study was conducted to investigate the influence of various reaction parameters on glycerol conversion and GC yield such as catalyst loading, temperature, CO2 pressure, time, and solvent concentration. The intensified process resulted into 57.4 % glycerol conversion with 57.2 % GC yield and 99.65 % selectivity. Moreover, the in-depth physicochemical characterisations of the synthesised MMO catalyst were conducted by using various surface analytical techniques. The synthesised MMO has showed a synergistic and protagonistic effect for direct carbonylation of glycerol. The recyclability study was performed to examine the robustness and efficency of the MMO catalyst that showed the consistency in the GC yield, conversion and selectivity without any significant loss after six consecutive runs. Also, the plausible reaction mechanism over MMO catalyst was proposed. The reported methodology has explored a simple, robust and efficient process for direct carbonylation of glycerol by using MMO catalyst with higher yield and selectivity of GC.