Vapor phase transport synthesis of CoAPO-5 molecular sieve and its catalytic performance

Co-substituted aluminophosphate molecular sieves (CoAPO-5) were synthesized by vapor-phase transport. The influence of the gel composition on the products was investigated. The catalyst physicochemical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared (FT-IR) and ultra-voilet absorption spectroscopy (UV-Vis DRS). The results showed that the synthesis conditions affected on the crystalline phase, the acidity, and thereby the catalytic performance of CoAPO-5. CoAPO-5 molecular sieves with AFI topology could be synthesized by crystallizing the gel for 48 h at 200°C, while the molar ratio of Al₂O₃, P₂O₅, CoO, (PrO)₃N to H₂O was 1:1:0.2:1:200 and the volume ratio of triethanolamine to H₂Owas 1:0 in the liquid phase. The yield of the ester was 93.2% under the conditions of molar ratio of acetic acid to n-butanol 4:1, reaction temperature 115°C and the mass fraction of catalyst 1% after reaction 5 h.