摘要
ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have beensynthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO_2,silica sol as the source of aluminum and silica, respectively, and TEA^+ as the template undercontrolled condition of the synthesis. The ZSM-5/β co-crystalline zeolite was studied by XRD, SEM,BET and NH_3-TPD. The reaction activity of toluene alkylation was investigated with a mixture oftoluene-methanol as the feedstock in a pulse micro-reactor over the ZSM-5/β co-crystalline zeolite.It is found that ZSM-5/β co-crystalline zeolite has two kinds of zeolite structure including ZSM-5and β zeolite, not in the form of a physical mixture. The pore structure of ZSM-5/βco-crystalline zeolites is different from that for β zeolite, ZSM-5 and their physical mixture. Inaddition, the peaks of both high and low temperature desorption of ammonia over the ZSM-5/βco-crystalline zeolite shift 23℃ to lower temperatures and the acid amount of its strong acid is 3%more than the physical mixture. So the ZSM-5/β co-crystalline zeolite produces the highest contentof xylene, which is 10.4% higher than the physical mixture. And the ZSM-5/β co-crystalline zeolitehas better selectivity for toluene alkylation and weaker de-methylation than β zeolite, ZSM-5 andtheir physical mixture.
ZSM-5/β co-crystalline zeolites with different content of ZSM-5 have beensynthesized by adding different amount of ZSM-5 to the synthetic system of β zeolite with NaAlO_2,silica sol as the source of aluminum and silica, respectively, and TEA^+ as the template undercontrolled condition of the synthesis. The ZSM-5/β co-crystalline zeolite was studied by XRD, SEM,BET and NH_3-TPD. The reaction activity of toluene alkylation was investigated with a mixture oftoluene-methanol as the feedstock in a pulse micro-reactor over the ZSM-5/β co-crystalline zeolite.It is found that ZSM-5/β co-crystalline zeolite has two kinds of zeolite structure including ZSM-5and β zeolite, not in the form of a physical mixture. The pore structure of ZSM-5/βco-crystalline zeolites is different from that for β zeolite, ZSM-5 and their physical mixture. Inaddition, the peaks of both high and low temperature desorption of ammonia over the ZSM-5/βco-crystalline zeolite shift 23℃ to lower temperatures and the acid amount of its strong acid is 3%more than the physical mixture. So the ZSM-5/β co-crystalline zeolite produces the highest contentof xylene, which is 10.4% higher than the physical mixture. And the ZSM-5/β co-crystalline zeolitehas better selectivity for toluene alkylation and weaker de-methylation than β zeolite, ZSM-5 andtheir physical mixture.
