347 / 2018-07-31 16:34:36

Hydrodeoxygenation of ethanol organosolv lignin to monoaromatics by metal–organic frameworks

全体主题 > 生物质液体燃料

The catalytic properties of nanoporous materials known as metal−organic frameworks (MOFs) are attracting considerable attention as a result of their exceptional chemical and structural versatility. For instance, metal nanoparticles (NPs) immobilized inside MOF pores are known to catalyze various chemical processes, including hydrogenation reactions and C-O bond cleavage. The objective of this study was to screen the best base catalyst to depolymerize ethanol organosolv lignin (EOL) yielding the highest quantity of phenolic monomeric compounds. We synthesized four series of Ni-, Co-, Cu- and Zn-based MOF-74 and used them to depolymerization lignin under mild conditions. The depolymerization of EOL was processed in the co-solvents of formic acid/water at 200°C for 8 h with the protection of H2. The efficiency of converting EOL into the hydrocarbons or aromatics depended on the types of catalysts. It increased with the order of Ni-MOF-74 > Cu-MOF-74 > Co-MOF-74 > MOF-74. The converting efficiency as high as 90wt% and the yield of phenols was more than 11wt%. All of the results showed that lignin can be efficiently degraded into aromatic hydrocarbons through the hydrogenation and deoxygenation reaction with MOFs as catalyst. It was also highlighted that MOF-based catalysts were potentially used in the selective cleavage of aryl-ether bonds in lignin and other biopolymers.