乳酸催化转化制备2，3-戊二酮

Catalytic Conversion of Lactic Acid to 2,3-Pentanedione

采用浸渍负载法制备了分子筛担载的钾催化剂K/Zeo(Zeo=ZSM-5,Y),研究了分子筛及K/Zeo对乳酸制备2,3-戊二酮的催化活性.对催化剂进行了X-光衍射和低温氮气吸附表征.结果表明,改性过程导致分子筛的骨架结构在一定程度上的破坏,比表面积、孔体积减小,而孔径增加.催化剂反应性能评价及碳平衡研究表明,与改性前相比较,改性后的催化剂反应性能和碳平衡率明显提高,这种结果可归因于改性后催化剂中新活性中心的形成及孔径的调变.在各种改性后的催化剂中,微-介孔ZSM-5催化剂性能最佳(在280℃时,乳酸转化率52.4%,PDO选择性48.0%),其原因在于该催化剂具有最高的比表面积.

A series of KNO3 modified zeolite catalysts（K/Zeo,Zeo = ZSM-5 , Y）were prepared in im- pregnation method and employed in the conversion of lactic acid to 2, 3-Pentanedione （PDO）. The charac- terizations of XRD and low-temperature N2-physisorption indicated that the process of KNO3 modification damaged to some extent the framework of zeolites, resulting in the decrease of specific surface area and pore volume but the increase of the pore size of the zeolites. The catalytic performance evaluation and car- bon balance examination have shown that, compared with those over the unmodified zeolite catalysts, both PDO yield and carbon balance are greatly improved, due to the generation of new active sites and the ad- justment of pore sizes, over the modified ones. Among various modified catalysts, a K/NaZSM-5 （60）, which possesses a micro-mesoporous structure, exhibits the best performance, providing 52.4 % lactic acid conversion and 48% PDO selectivity at 280 ℃. The high performance of this catalyst may be the result of its large specific surface area.