title: N-methyldiethanolamine: a multifunctional structure-directing agent for the synthesis of SAPO and AlPO molecular sieves.
abstract: In the present study, N-methyldiethanolamine (MDEA) is demonstrated to be a multifunctional structure-directing agent for the synthesis of aluminophosphate-based molecular sieves. Four types of molecular sieves, including SAPO-34, -35, AlPO-9 and -22, are for the first time acquired with MDEA as a novel template. The phase selectivity of the present synthesis is found to be condition-dependent. SAPO-34 (CHA) crystallizes from a conventional hydrothermal system with a higher MDEA concentration. When using MDEA as both the template and solvent, pure SAPO-35 (LEV) is obtained from the synthetic gel with a high P2O5/Al2O3 ratio of (2-3), in which the concentration of MDEA could be varied in a wide range. AlPO-9 and AlPO-22 (AWW) are synthesized under the similar conditions to SAPO-35, except without the addition of Si source. The physicochemical properties of the obtained samples are investigated by XRD, XRF, SEM, N2 physisorption, TG-DSC, and various NMR spectra ((13)C, (29)Si, (27)Al and (31)P). Both SAPO-34 and SAPO-35 show good thermal stability, large surface area, and high pore volume. The catalytic performance of SAPO-34 is evaluated by the methanol-to-olefins (MTO) reaction and a good (C2H4+C3H6) selectivity of 82.7% has been achieved.
authors.affiliation: National Engineering Laboratory for Methanol to Olefins, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Dehua
authors.initials: D
authors.lastname: Wang
authors.affiliation: National Engineering Laboratory for Methanol to Olefins, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Tian
authors.affiliation: National Engineering Laboratory for Methanol to Olefins, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Fan
authors.affiliation: National Engineering Laboratory for Methanol to Olefins, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
authors.forename: Miao
authors.initials: M
authors.lastname: Yang
authors.affiliation: National Engineering Laboratory for Methanol to Olefins, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Gao
authors.affiliation: National Engineering Laboratory for Methanol to Olefins, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Yuyan
authors.initials: Y
authors.lastname: Qiao
authors.affiliation: National Engineering Laboratory for Methanol to Olefins, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Chan
authors.initials: C
authors.lastname: Wang
authors.affiliation: National Engineering Laboratory for Methanol to Olefins, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China; Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China. Electronic address: liuzm@dicp.ac.cn.
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Liu
keywords: Alkanolamine; MTO reaction; SAPO; Structure-directing agent; Synthesis