钯/炭催化剂对碱木质素还原反应的催化作用

采用甲醛还原法制备钯/炭(Pd/C)催化剂,考察了以Pd/C为催化剂,以环己烯为氢给予体的催化体系对麦秆碱木质素还原反应的催化作用,用化学法对反应前后碱木质素官能团进行了定量测定,用FTIR、UV和1H NMR光谱对木质素化学结构进行了分析.结果表明,Pd/C催化剂对碱木质素还原反应具有较高的催化活性,碱木质素总羟基含量增加了46.95%,酚羟基含量增加了33.74%,醇羟基含量增加了63.93%;甲氧基含量降低了17.73%,羧基含量降低了53.41%,总酸性基变化不大,木质素的苯环结构稳定,活性官能团增加,反应活性提高,PdC催化剂对木质素还原活化反应具有良好的催化作用.

Catalytic Effect of Pd/C Catalyst on Deoxidizing of Straw Alkali Lignin

The Pd/C catalyst was prepared by formaldehyde deoxidation method and the catalytic effect of active carbon supported palladium on the deoxidizing reaction of alkali lignin from the straw was investigated. The functional groups of the straw alkali lignin were determined quantitatively befor and after reaction ,the chemical structure of the lignin was analyzed by means of FTIR,UV and 1H-NMR.The results indicated that the Pd/C catalyst had better catalytic effect on the deoxidizing reaction of straw alkali lignin. It was found that the content of total hydroxyl increased 49.95 %,the phenolic hydroxyl increased 33.74 %,the aliphatic hydroxyl increased 63.93%,on the other hand the methoxyl group decreased 17.73%;the content of carboxyl reduced 53.41% and the total acidic group had little changes;the phenyl structure of lignin was steady.The active functional group of alkali lignin was increased so that the reactive activity was enhanced.