Synthesis of glycerol carbonate from glycerol and CO₂ over Cu-Zr complex oxide

A series of Cu_1−xZr_xO₂ bimetallic oxides with different Cu-Zr molar ratios for glycerol carbonate synthesis from glycerol and CO₂ were prepared by hydrothermal method. The results found that the performance was significantly affected by the Zr doping amounts. Under the optimal reaction conditions, the Cu_0.99Zr_0.01O₂ catalyst had the best catalytic performance. The conversion of glycerol and the selectivity of glycerol carbonate reached 64.1% and 85.9%, respectively. Cu_1−xZr_xO₂ complex oxide exhibited better activity than pure CuO and pure ZrO₂. The structures, morphologies and surface properties of the catalysts were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N₂ adsorption and desorption, Temperature programmed reduction (H₂-TPR), Temperature programmed desorption (TPD) and Fourier Transform Infrared Spectroscopy (FT-IR). It is speculated that the high activity is related to the degree of dispersion of Zr on the surface of CuO, the surface content of oxygen species and the number of acidic-basic sites. In addition, catalytic activity did not change significantly after six cycles, indicating the excellent stability of the catalyst.