杂多酸离子液体催化燃油萃取氧化脱硫性能研究

本文首次将一系列含有不同酸性咪唑阳离子和不同杂多酸阴离子的杂多酸离子液体C4mim]3PW12O40、COOH-Cmim] 3PW12O40、SO3H-C3mim]3PW12O40、SO3H-C3mim]3PMo12O40和SO3H-C3mim]4 SiW12O40作为催化剂,乙腈为萃取剂,H2O2为氧化剂,用于催化含二苯并噻吩、苯并噻吩及噻吩模型油的萃取氧化脱硫研究中.实验结果显示,杂多酸离子液体催化燃油脱硫性能不仅与阳离子的酸性强弱有关,而且与阴离子结构密切相关.阳离子的催化活性顺序为:SO3H-C3mim]+＞COOH-Cmim]+＞C4mim]+;阴离子的催化活性顺序为PW12O403-＞ PMo12O403-＞ SiW12O404-.其中SO3H-C3 mim]3 PW12O40催化活性最高,在60℃反应40min的条件下,二苯并噻吩的转化率约为100％,催化不同硫化物的转化率为:二苯并噻吩＞苯并噻吩＞噻吩.此外,该杂多酸离子液体循环使用5次催化活性仅略有下降.

Extraction and Oxidative Desulfurization of Fuels Catalyzed by Polyoxometalate-Based Ionic Liquids

A series of polyoxometalate-based ionic liquids (POM-ILs) C4mim]3PW12O40, COOH-Cmim]3PW12O40, SO3H-C3mim]3PW12O40, SO3H- C3mim]3PMo12O40 and SO3H-C3mim]4SiW12O40 were applied as catalysts for the removal of dibenzothiophene (DBT), benzothiophene (BT) and thiophene (T) in model oil with H2O2 as oxidant and acetonitrile as extractant. The experimental results showed that the acidity of cations and the type of anions of the POM-ILs all played key roles for catalyzing desulfurization reaction. The catalytic activities of the cations followed the order of SO3H-C3mim] > COOH-Cmim] > C4mim] and the order of anions was PW12O403- > PMo12O403- > SiW12O404-. Under the optimized conditions, the catalyst SO3H-C3mim]3PW12O40 showed the highest activity with DBT conversion of about 100% at 60 oC for 40 min. And its sulfur removal selectivity for S-compounds followed the order of DBT > BT > T. Additionally, the catalyst can be recycled five times with a slight decrease in activity.