Synthesis of Zirconium Modified Hierarchical Sapo-34 Catalysts using Carbon Nanotube Template for Conversion of Methanol to Light Olefins

Two types of zirconium-containing hierarchical SAPO-34 catalysts were successfully synthesized by isomorphous substitution and impregnation methods and applied for the conversion of methanol to light olefins. Carbon nanotube was employed as a mesopore template to create mesopores in the crystals of SAPO-34. Physical and chemical characterizations of the catalysts demonstrated that the modification of SAPO-34 with Zr by isomorphous substitution and impregnation methods gives rise to differences in acidity, porosity and crystal size. MTO results showed that the lifetime of the catalysts was in the order of ZrAPSO-34 > SAPO-34 > Zr/SAPO-34 while the selectivity to ethylene was in the order of Zr/SAPO-34 > ZrAPSO-34 > SAPO-34.