Observation of heptamethylbenzenium cation over SAPO-type molecular sieve DNL-6 under real MTO conversion conditions

Jinzhe Li; Yingxu Wei; Jingrun Chen; Peng Tian; Xiong Su; Shutao Xu; Yue Qi; Quanyi Wang; You Zhou; Yanli He; Zhongmin Liu

doi:10.1021/ja209950x

Observation of heptamethylbenzenium cation over SAPO-type molecular sieve DNL-6 under real MTO conversion conditions

J Am Chem Soc. 2012 Jan 18;134(2):836-9. doi: 10.1021/ja209950x. Epub 2011 Dec 23.

Authors

Jinzhe Li¹, Yingxu Wei, Jingrun Chen, Peng Tian, Xiong Su, Shutao Xu, Yue Qi, Quanyi Wang, You Zhou, Yanli He, Zhongmin Liu

Affiliation

¹ National Engineering Laboratory for Methanol to Olefins, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.

PMID: 22191624
DOI: 10.1021/ja209950x

Abstract

The heptamethylbenzenium cation (heptaMB(+)) has been speculated to be one of the most important active intermediates involved in the "hydrocarbon pool" mechanism of methanol-to-olefin (MTO) conversion. By the use of DNL-6, a newly synthesized SAPO-type molecular sieve with large cavities, heptaMB(+) has for the first time been directly observed during methanol conversion under real working conditions. (13)C-labeling experiments suggested that olefin formation mediated by heptaMB(+) mainly follows the side-chain mechanism.