碱水体系下CeO_2和La_2O_3催化解聚木质素的研究

Studies on lignin depolymerization by CeO_2 and La_2O_3 in alkaline systems

将两种稀土元素的氧化物CeO2和La2O3分别添加到碱水溶液中,并对该体系下的木质素解聚能力进行了研究.实验结果表明:两种催化剂都可以很好地将木质素解聚成多聚体、二聚体和单酚类产物,同时单酚类产物也可以继续裂解生成分子量更小的物质.在反应温度为230250℃时,CeO2体系可以生成更多的单酚类产物,在反应温度为250260℃时,La2O3体系更有利于单酚类产物的生成.其中2-甲氧基苯酚和邻苯二酚是单酚类产物中最主要的两种产物.

Abstact: Two rare-earth element catalysts CeO_2 and La_2O_3 were added to an alkaline systems,respectively,and the lignin catalytic depolymerization activities of the two catalysts were investigated. The results suggest that lignin can be depolymerized into polymers,dimers and monophenols effectively by the two catalysts,and monophenols can also be cracked to generate smaller molecular weight material. CeO_2 can generate more monophenols at reaction temperatures of 230 ~ 250 ℃,while La_2O_3 is more conducive to the production of monophenols at 250 ~ 260℃. 2-methoxyphenol and catechol are the two most main products in the monophenols.