Transforming glycerol and CO 2 into glycerol carbonate over La 2 O 2 CO 3 –ZnO catalyst — a case study of the photo-thermal synergism

The direct synthesis of glycerol carbonate via glycerol carbonylation by CO 2 suffers from thermodynamic limitation. In this study, light was introduced into the thermal-driven reaction system to synergistically break the equilibrium of the reaction. A series of x La 2 O 2 CO 3 –ZnO catalysts were prepared using a hydrothermal method and used for the photo-thermal transformation of glycerol and CO 2 into glycerol carbonate. Inductively coupled plasma-atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), CO 2 temperature-programmed desorption (CO 2 -TPD), X-ray photoelectron spectroscopy (XPS), UV-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy and Fourier transform infrared (FT-IR) spectrometry were employed to characterize the crystalline structure, the number of basic sites, textural properties and optical properties of the catalysts. The photo-thermal synergism as well as the cooperation between ZnO and La 2 O 2 CO 3 contributed to its catalytic performance, thus achieving a glycerol conversion of 6.9% under the reaction conditions of 150 °C, 5.5 MPa CO 2, and 20 mmol GL g Cat −1 with a reaction time of 6 h when 20% La 2 O 2 CO 3 –ZnO was used as the catalyst.