Unveiling activity of ZIF-8/nickel loaded alumina aerogel catalyst in glycerol carbonate production from CO2 and glycerol

Abstract

Glycerol Carbonate (GC) production via carbonylation of glycerol with CO2 reaction takes attention to its properties of enabling both the utilization of biodiesel by-product glycerol and the use of major greenhouse gas CO2. Herein, the synthesis of GC via glycerol carbonylation with CO2 over a series of ZIF-8 on nickel-loaded Alumina Aerogel catalysts was examined for the first time in literature. ZIF-8 growth on nickel-impregnated Alumina aerogel was executed using an in situ method. Synthesized catalysts were analyzed using SEM–EDX, FT-IR, DRIFTS, XRD, and N2 sorption techniques. The carbonylation reaction of glycerol was conducted in the presence of a co-reactant (propylene oxide) and solvent (methanol). The influence of reaction parameters (temperature, catalyst loading, glycerol/co-reactant molar ratio, co-reactant type, catalyst type, and reaction time) on the catalytic activity (glycerol conversion, GC selectivity and yield) of the catalysts were investigated. It obtained high glycerol conversion (73%) for AA-2Ni-5ZIF, yield (31%), and selectivity (77%) of GC for AA-5Ni-15ZIF under optimized reaction conditions (150 °C, 7 bar, 2 h, 6% catalyst loading and 0.5 glycerol/propylene oxide). Compared to the literature, this activity was found under lower CO2 pressure and reaction time. Unique features of catalysts such as suitable acidity, high surface area, more than one active crystal, and the presence of propylene oxide as a co-reactant promoted the rise of glycerol conversion, GC selectivity, and yield.