Catalytic mechanisms of potassium salts on pyrolysis of -O-4 type lignin model polymer based on DFT study

In this study, the possible catalytic mechanisms of potassium salts on lignin pyrolysis was investigated with two /3-O-4 type lignin model dimers with different oxygen functional groups on C a using density functional theory (DFT) calculations. It was found that potassium salts (such as KOH and K 2 CO 3 ) can react with phenol hydroxyl in lignin to form organic-K and further catalyze pyrolysis progress. Through this catalytic mechanism, potassium salts promoted the removal of C a on specific intermediates and the demethylation of methoxy groups during /3-O-4 type lignin pyrolysis, promoted the decomposition of intermediates, and facilitated the formation of phenol and CO 2 . ? 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.