Simulated 13C chemical shifts used to investigate zeolite catalysis

Abstract

Zeolites have been successfully applied on a wide range of reaction processes (Methanol to Hydrocarbons, Fluid Catalytic Cracking, etc) and continue to attract academic and industrial investigations. Understanding of the reaction mechanisms involved in zeolite catalysis has been a long standing issue due to the wide range of intermediates and products involved, which has hindered the industrial implementation of these materials. Thus, in order to determine and discriminate between each type of compound involved in the complex reaction mixture, computational simulations have been applied to analyse the 13C chemical shifts of a wide range of known or proposed intermediates and products. The first part of this study focuses on calculating the 13C chemical shifts of C1-C3 compounds commonly part of the reactant feed, comparing the results of mobile versus immobile states and determining which compounds could have their 13C chemical shifts superimposed over others. The second part focuses on C4-C6 olefins, analysing the differences stemming from: position of double bond, ramified structure, mobile and chemical state. Finally, the third part translates the same approach from the olefins study on aromatic derivatives.