Solution-Sensitivity and Comprehensive Mechanism of Lignin Breakdown during the Phosphoric Acid-Acetone Pretreatment Process

Abstract

This work focused on the solution-sensitivity and the comprehensive mechanism of lignin breakdown during the phosphoric acid-acetone pretreatment process using density functional theory calculations. The

Production of phenolics via photocatalysis of ball milled lignin–TiO2 mixtures in aqueous suspension

“…HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), and band gap of lignin. 35 The interactions are further validated by analyzing the FT-IR and photoluminescence spectra of the mixtures as discussed in the next section. no.…”

“…Using quantum chemistry calculations, it was shown that water and acetone greatly modify the electronic states (HOMO and LUMO) and band gap associated with a-O-4 and bb bonds of lignin. 35 For example, the valence band and conduction band edges of TiO 2 are À7.46 eV (vs. vacuum) and À4.26 eV, respectively, 42 and the HOMO and LUMO states of a-O-4 of lignin in water solvent are À5.076 eV and À1.714 eV, respectively. 35 This shows that the electron transfer can occur from conduction band of TiO 2 to HOMO of lignin during excitation.…”

“…35 For example, the valence band and conduction band edges of TiO 2 are À7.46 eV (vs. vacuum) and À4.26 eV, respectively, 42 and the HOMO and LUMO states of a-O-4 of lignin in water solvent are À5.076 eV and À1.714 eV, respectively. 35 This shows that the electron transfer can occur from conduction band of TiO 2 to HOMO of lignin during excitation. This trapped electron can initiate reactions in lignin.…”