title: Regulating acidity, porosity, and morphology of hierarchical SAPO-11 zeolite by aging treatment.
abstract: A facile method to modify pore structure, acidic character, and morphology of SAPO-11 molecular sieve was proposed. Aging treatment (e.g., microwave irradiation or lyophilization) is introduced in the preparation of dry gel. It regulates the kinetics of zeolitic nucleation and growth. X-ray diffraction, scanning electron microscopy, N2-adsorption, temperature programmed desorption, laser particle analyzer, and (29)Si MAS NMR were employed to investigate the effects of aging treatments on SAPO-11 products. The experimental results indicate that depolymerization reaction of silicon species is enhanced aged by microwave irradiation with a higher temperature (90°C). Ratio of SM 3 to SM 2 substituting mode increases producing more strong Brønsted acid sites. Lyophilization technology, as another aging method, was employed to control the morphology of SAPO-11. Nano-sized hierarchical SAPO-11 molecular sieve (200nm in length) is obtained with an oriented growth. Activity of hydroisomerization catalysts is regulated by aging treatment. Cracking reaction attributes to a high conversion nearly 87wt% for M90. The hydroisomerization reaction is enhanced for M40 due to a large proportion of moderate acid sites.
authors.affiliation: State Key Laboratory for Heavy Oil Processing, Key Laboratory of Catalysis, CNPC, China University of Petroleum, Qingdao 266580, China. Electronic address: lyx_1989@126.com.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Heavy Oil Processing, Key Laboratory of Catalysis, CNPC, China University of Petroleum, Qingdao 266580, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory for Heavy Oil Processing, Key Laboratory of Catalysis, CNPC, China University of Petroleum, Qingdao 266580, China.
authors.forename: Yuchao
authors.initials: Y
authors.lastname: Lv
authors.affiliation: State Key Laboratory for Heavy Oil Processing, Key Laboratory of Catalysis, CNPC, China University of Petroleum, Qingdao 266580, China. Electronic address: lxmei@upc.edu.cn.
authors.forename: Xinmei
authors.initials: X
authors.lastname: Liu
keywords: Aging; Dry gel conversion; Lyophilization; Microwave; SAPO-11