Synthesis of crystalline ordered mesoporous CaO–ZrO2 solid solution as a promising solid base

The crystalline CaO–ZrO2 mesoporous solid solution have been fabricated by a simple one-step procedure with zirconyl chloride octahydrate (ZrOCl2·8H2O) and calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) as metal precursors and triblock co-polymer of Pluronic P-123 as templating agent. Small-angle X-ray diffraction (SXRD) and transmission electron microscopy (TEM) results shows that ordered mesoporous structure and worm-like mesoporous structure were obtained when the molar ratio of Ca/Zr were 0.25 and 0.5. Wide angle X-ray diffraction (WXRD) and Raman spectra indicated that the formation of homogeneous solid solution was responsible for the stable cubic phase. All CaO–ZrO2 solid solutions were endowed with strong basicity (H− = 9.3–12.2). The incorporation of Ca2+ into ZrO2 lattice led to the formation of solid solution structure and which could effectively improve the thermal stability and inhibit basic sites from leaching in the reaction.