Synthesis of mesoporous chromium aluminophosphate (CrAlPO) via solid state reaction at low temperature

Abstract

Mesoporous chromium aluminophosphate (CrAlPO) was successfully synthesized via solid state reaction (SSR) route at low temperature in the presence of a cationic surfactant cetyltrimethyl ammonium bromide (CTAB) and inorganic sources such as AlCl3·6H2O, CrCl3·6H2O and NaH2PO4·2H2O. Characterizations by means of powder X-ray diffraction (XRD), N2 adsorption-desorption, high resolution transmission electron microscopy (HR-TEM), scanning electron micrography (SEM), energy dispersion spectroscopy (EDS), thermo-gravimetry (TG), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet visible light spectroscopy (UV-Vis) were carried out to understand both the pore characteristics and electron transition route of these obtained materials. The experimental results show that the meso-CrAlPO materials with various Cr/Al molar ratios possess a mesostructure and a specifi c surface area of 193 to 310 m2/g corresponding to an average pore size of 5.5 to 2.2 nm, respectively. The maxium content of Cr in meso-CrAlPO materials synthesized via SSR route can achieve 16.7wt%, being significantly higher than that of the meso-CrAlPO prepared via a conventional sol-gel route. Meanwhile, the formation mechanism of the meso-CrAlPO was also proposed.