文献类型：期刊文献

英文题名：Steam-assisted synthesis of SAPO-34@ZSM-5 core-shell zeolite for enhancing the synergies of n-hexane-Methanol Co-Reaction to light olefins

作者：Cheng, Qitong[1];Shen, Benxian[1,2];Liu, Jichang[1,2];Sun, Hui[1,2];Wu, Di[3];Jiang, Lei[1];Yan, Peikun[1];Pu, Xin[1];Ou, Suhui[1];Zhao, Jigang[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Int Joint Res Ctr Green Energy Chem Engn, Shanghai 200237, Peoples R China;[3]Washington State Univ, Dept Chem, Pullman, WA 99163 USA

年份：2021

卷号：324

外文期刊名：MICROPOROUS AND MESOPOROUS MATERIALS

收录：;EI(收录号：20213110695929);WOS:【SCI-EXPANDED(收录号:WOS:000715852800004)】；

基金：The authors would like to acknowledge financial support from Joint Fund by the National Natural Science Foundation of China and Petro-China (Project U1862204).

语种：英文

外文关键词：Core-shell configuration; Steam-assisted synthesis; Co-reaction; Composite zeolites; Light olefins

摘要：An alternative and promising route for the production of light olefins which realizes the objective of effective resource usage is the coupling conversion of n-hexane-methanol. The SAPO-34@ZSM-5 core-shell composite has been designed and fabricated by the steam-assisted crystallization (SAC) method for boosting the n-hexanemethanol synergies. SAC avoids the undesired phase transformation/dissolution of SAPO-34 caused by exposure to harsh basic conditions of the ZSM-5 precursor solution. In comparison with the nanosized ZSM-5 or physical mixture, the SAPO-34@ZSM-5 core-shell zeolite demonstrates a 32-38 wt% increase in the light olefin selectivity, a 28-67 wt% increase in the n-hexane conversion, and an 89-143% improvement in the catalyst lifetime under identical reaction conditions. With the aid of GC-MS analysis of carbonaceous deposits in spent catalysts, higher polymethylbenzenes concentration and lower polycyclic aromatic hydrocarbon (PHA) concentration are obtained from the extracted species of spent SAPO-34@ZSM-5 in comparison with that of other samples, which suggests the aromatic-based route to light olefins is enhanced and the carbonaceous deposition is slowed down. The core-shell configuration of the SAPO-34@ZSM-5 composite diminishes the diffusion rate of methanol towards the SAPO-34 core layer and increases the coupling of n-hexane derivatives with methanol in the hydrocarbon pool (HCP) route. The decreased number of acidic sites on the external surface of the SAPO-34 core layer may also be accounted for the inhibited carbon deposition.