Nano-europium oxide catalyzed lignin oxidation

Lignin is the only large-scale renewable source of aromatic compounds, and has the advantages of being inedible, widely available and cheap. A wide range of aromatic aldehydes, acids and esters can be obtained by directional catalytic oxygenation of polylignin. Catalysts are the key to directional catalytic depolymerization of poly (lignin). Rare earth oxides show unique properties in catalytic oxidation reaction, but the performance of nano rare earth oxides in polyphase catalytic depolymerization of lignin is rarely reported. In this paper, the nanoparticle europium oxide (Eu2O3) catalyst was prepared by hydrothermal method. Firstly, the catalytic oxidation of lignin model molecule 2-(2, 6-dimethoxyphenyl) -1-phenylethanol (DP-OL) was carried out, and the optimal catalytic conditions (220℃,1) were obtained MPa oxygen,50% methanol aqueous solution,4 h) and highest conversion rate (72.24%). The main products were benzoic acid, methyl benzoic acid and acetophenone by GC-MS detection. It was proved that β-O-4 and Cα -c β were broken in the lignin model molecule. Secondly, the catalyst was used to catalyze the oxygen-depolymerization of real lignin, and the main products were dimethyl succinate, dimethyl 2-methoxysuccinate, tetramethylphthalate and other products. Nano Eu2O3 particle catalyst is easy to prepare, low price, and has good research value and application prospect.