In the present study, we utilize the eggshell (mainly composed of lysozyme and CaCO3) to induce the silicificaiton of Na2SiO3 (a SiO2 precursor), thus acquiring the CaCO3–SiO2 composites. After calcination, the as-obtained CaCO3–SiO2 composites could be con- verted into the CaO–SiO2 catalysts, where SiO2 is primarily attached on the surface of CaO. Afterwards, the physicochemical properties of the prepared CaO–SiO2 catalysts are characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), 29Si NMR spectrometer, Fourier transform infrared (FTIR) spectrometer, X-ray diffraction (XRD), Brunauer– Emmett–Teller (BET) analysis and the Hammett indicator method. The effects of reaction conditions (such as reaction time, reaction temperature, methanol-to-oil molar ratio and amount of catalyst loading) and the catalyst reusability are also thoroughly studied