Based on the preparation of supported catalytic packing(SCP)by polydopamine-assisted secondary growth method,a high-performance SCP preparation method was developed through multiple crystallization and alkali treatment synergistic modification.It was found that the loading of the active component layer on SCP increases linearly with the number of crystallization steps.However,the excessively dense structure of the active component layer hinders the utilization of active sites.Tetramethylammonium hydroxide(TMAOH)treatment,by dissolving silicon atoms to create mesopores,enhances the external specific surface area and diffusion efficiency,thereby improving the catalytic activity and coke accommodation capacity of SCP.Under the optimized modification conditions,that is,with 3 crystallization times,a TMAOH solution concentration of 0.05 mol/L,an alkaline treatment temperature of 80℃,and an alkaline treatment time of 120 min,the activity of SCP is increased by 3.74 times.Although the activity decreases during the synthesis of cyclohexyl acetate from acetic acid and cyclohexene,the activity can be restored through calcination regeneration.The coke resulting from the high-temperature polymerization of cyclohexene is the primary cause of activity reduction.
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