Inorganic Chemicals Industry ›› 2020, Vol. 52 ›› Issue (7): 88-93.doi: 10.11962/1006-4990.2019-0444

• Catalytic Materials • Previous Articles     Next Articles

Process regulation of ZSM-5 zeolite synthesis from hydrolyzed tetraethyl orthosilicate as silicon source in acidic medium

Chen Yanguang1,2,Han Tong1,2,Zhang Yanan1,2,Yang Xiuqi1,2,Han Hongjing1,2,Wang Hao1,2   

  1. 1.College of Chemistry and Chemical Engineering,Northeast Petroleum University,Daqing 163318,China
    2.Heilongjiang Provincial Key Laboratory of Oil and Gas Chemical Technology
  • Received:2020-01-26 Online:2020-07-10 Published:2020-07-13

Abstract:

Tetraethyl orthosilicate(TEOS) is usually used as the silicon source for the synthesis of ZSM-5 zeolite.The polymerization state of the precursors hydrolyzed in different acid-base media had a regulatory effect on the grain size and pore size distribution of ZSM-5.The precursor of hydrolysis and condensation of TEOS in acidic medium was used as the silicon source.ZSM-5 was synthesized under hydrothermal conditions,and the samples at different stages during the reaction were characterized by XRD,SEM,BET and FI-IR.The effects of hydrolysis degree,hydrolysis time,pH of synthesis process,crystallization temperature,crystallization time and template dosage on the synthesis of ZSM-5 zeolite were investigated.The results showed that when the ethanol was used as co-solvent,the precursor of TEOS hydrolyzed for 20 h in sulfuric acid medium(pH=2.0) was used as silicon source,tetrapropylammonium hydroxide(TPAOH) was added during the hydrothermal synthesis process,and Al(OH)3 was used as aluminum source,the ZSM-5 zeolite with the crystal grain size(about 200 nm) was synthesized that crystallized at 180 ℃ for 30 h.The specific surface area of ZSM-5 zeolite was increased by 35.6% and the average pore size was decreased by 48.6%.

Key words: acid hydrolysis, hydrothermal synthesis, ZSM-5 zeolite, tetraethyl orthosilicate

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