Transformation of CO2 with Glycerol to Glycerol Carbonate over ETS-10 Zeolite-Based Catalyst.

Catalytic conversion of CO2 with the surplus glycerol (GL) produced from biodiesel manufacturing has attracted much academic and industrial attention, which proves the urgent requirement for developing high-performance catalysts to afford significant environmental benefits. Herein, titanosilicate ETS-10 zeolite-based catalysts with active metal species introduced by impregnation were employed for coupling CO2 with GL to efficiently synthesize glycerol carbonate (GC). The catalytic GL conversion at 170 °C miraculously reached 35.0% and a 12.7% yield of GC was obtained on Co/ETS-10 with CH3CN as a dehydrating agent. For comparison, Zn/ETS- Cu/ETS-10, Ni/ETS-10, Zr/ETS-10, Ce/ETS-10, and Fe/ETS-10 were also prepared, which showed inferior coordination between GL conversion and GC selectivity. Comprehensive analysis revealed that the presence of moderate basic sites for CO2 adsorption-activation played a crucial role in regulating catalytic activity. Moreover, the appropriate interaction between cobalt species and ETS-10 zeolite was also of great significance for improving the glycerol activation capacity. A plausible mechanism was proposed for the synthesis of GC from GL and CO2 in the presence of CH3CN solvent over Co/ETS-10 catalyst. Moreover, the recyclability of Co/ETS-10 was also measured and it proved to be recycled at least eight times with less than 3% decline in GL conversion and GC yield after a simple regeneration process through calcination at 450 °C for 5 h in air.

Boosting CO2 hydrogenation to methane over Ni-based ETS-10 zeolite catalyst.

The activation and conversion of the CO2 molecule have always been the most vexing challenge due to its chemical inertness. Developing highly active catalysts, which could overcome dynamic limitations, has emerged as a provable and effective method to promote CO2 activation-conversion. Herein, ETS-10 zeolite-based catalysts, with active nickel species introduced by in situ doping and impregnation, have been employed for CO2 methanation. Conspicuous CO2 conversion (39.7%) and perfect CH4 selectivity (100%) were achieved over the Ni-doped ETS-10 zeolite catalyst at 280°C. Comprehensive analysis, which include X-ray diffraction, N2 adsorption-desorption, SEM, TEM, H2 chemisorption, CO2 temperature programmed desorption, and X-ray photoelectron spectroscopy, was performed. Also, the results indicated that the resultant hierarchical structure, high metal dispersion, and excellent CO2 adsorption-activation capacity of the Ni-doped ETS-10 zeolite catalyst played a dominant role in promoting CO2 conversion and product selectivity.