PREPARATION OF MoO_3/gamma-Al_2O_3 CATALYST BY THE REACTION OF alpha-BOEHMITE WITH MoO_3/H_2O SLURRY - DUAL ROLE OF MoO_3 AS ACTIVE PHASE AND TEXTURE STABILIZER DURING CALCINATION

摘要

Catalyst MoO_3/gamma-Al_2O_3 was prepared by the reaction of alpha-boehmite with molybdic acid in slurry MoO_3/H_2O followed by calcination.The deposited MoO_3 functioned as thermal stabilizer and inhibited sintering of Al_2O_3 phase during calcination.After calcination at 550 and 650deg C the surface area of Al_2O_3 obtained from a-boehmite was 207 and 172 m~2 g~(-1),respectively,and of MoO_3/Al_2O_3 obtained from MoO_3/a-boehmite was 323 and 285 m~2 g~(-1),respectively.On the other hand,molybdic acid did not work as peptization agent and the mechanical strength of MoO_3/Al_2O_3 was not higher than that of Al_2O_3.The catalyst was sulfided and its activity in thiophene hydrodesulfurization was tested;it exhibited about the same activity as reference industrial MoO_3/Al_2O_3 catalyst.