Study on ZSM-5 catalytic pyrolysis mechanism of cellulose based on the Py-GC/MS and the density functional theory

In this study, Py-GC/MS and density functional theory (DFT) were used to analyze products and reaction mechanisms of cellulose undergone non-catalytic and catalytic pyrolysis by ZSM-5. The results showed that the main products of non-catalytic pyrolysis are furans, furfurals, aldehydes, ketones, carboxylic acids, esters and carbohydrate. While, in catalytic pyrolysis, the furan content decreased noticeably, and a new class of components (aromatic hydrocarbons) appeared. DFT studies exhibited that a hydrogen proton at acid sites of the catalyst was directly involved in most of the pyrolysis reactions of cellulose. Catalytic pyrolysis reduces the activation energy of dehydration and de-carbonylation by 40-70 kcal/mol and 86.05 kcal/mol, respectively, compared with non-catalytic pyrolysis. (C) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

In this study, the products and reaction mechanisms of cellulose during non-catalytic and catalytic pyrolysis with ZSM-5 catalyst were analyzed using Py-GC/MS and DFT. The results showed that catalytic pyrolysis reduced the furan content and introduced aromatic hydrocarbons as new components. DFT studies demonstrated the involvement of hydrogen proton at the catalyst's acid sites in most cellulose pyrolysis reactions. Catalytic pyrolysis significantly lowered the activation energy for dehydration and de-carbonylation compared to non-catalytic pyrolysis.