Manganese peroxidase Plus Cu(salen) Improving Delignification Selectivity of Pulp

Abstract

Lignin and carbohydrate model compounds were employed to study the performance of the one-pot catalysis combining MnP/MCM and Cu(salen)/NaY upon the delignification selectivity of bamboo kraft pulp. Phenolic lignin model compound was thus oxidised in the presence of refractory lignin model compound (2,2’-biphenol, LCC model compound and nonphenolic lignin model compound), and dextran was also oxidised in the presence of various lignin model compounds. The results showed that the combined catalyst allowed high conversion rate of phenolic lignin model compound according to the vanillin yield and low depolymerization rate of dextran according to the relative viscosity of solution compared to single neat and/or immobilized catalysts respectively in the presence of refractory lignin model compounds and all lignin model compounds. The effect of these lignin model compounds on the reaction selectivity was also evaluated and was found that their negative effects followed the order: 2,2’-biphenol>LCC model compound>nonphenolic lignin model>phenolic lignin model compound. At the same time, the experimental data of pulp delignification and lignin 31P-NMR analysis confirmed these findings. This means that the one-pot process catalyzed by ligninase and biomimetic complex may be potentially recommended for both pulp and biomass delignification.