微波辐射加热金属离子改性Hβ分子筛催化合成蒽醌

Synthesis Anthraquinone over Hβ Zeolites Modified by different

摘要:

摘要：在微波辐射加热下用不同金属离子（Al3+、Tl4+、Fe3+）对Hβ分子筛进行改性，并将其用于催化苯与苯酐合成蒽醌。采用XRD、 NH3-TPD和吡啶-IR对分子筛进行了表征。实验结果表明，微波辐射加热能提高分子筛的改性效率，并能有效地改善其催化性能，且对分子筛晶体结构没有破坏作用。不同金属离子改性的分子筛的催化效果差别很大，其中0.5 mol•L-1的Al2(SO4)3溶液改性的Hβ分子筛催化效果最好，蒽醌产率38.87 %，选择性92.78 %。分子筛的表面酸性质对其催化性能有较大影响，催化剂表面的中强度酸是催化活性中心，L酸量与B酸量的比值对分子筛的催化性能有着重要的影响。

Abstract:

Abstract: Hβ zeolites were modified by different metal ions (Al3+,Tl4+,Fe3+）under microwave radiation, and used to catalyze the synthesis of anthraquinone with benzene and phthalic anhydride. The modified zeolites were characterized by means of XRD, NH3-TPD and Pyridine-IR. The results showed that the microwave radiation was more effective for the modification of zeolite, and the catalytic performance of modified zeolites were improved. Microwave radiation did not destroy the crystal structure of β zeolite.There was great difference in catalytic activity among the zeolites modified by different metal ions. The zeolite modified with 0.5 mol•L-1 Al2(SO4)3 showed the best catalytic activity for the reaction, and the yield of anthraquinone was 38.87 %; selectivity reached 92.78 %. The surface acidity of zeolite had a significant influence on the catalytic performance in the synthesis of anthraquinone, and the medium strong acid sites were the active sites. The ratio of L acidity to B acidity played the important role in the catalysis reaction.