Keggin结构磷钼钨杂多酸的合成及其催化氧化燃油超深度脱硫的研究

Synthesis of Phosphorus-molybdenum-tungsten Heteropoly Acid with Keggin Structure and Their Catalytic Oxidation Performance in the Ultra-deep Desulfurization of Fuel Oil

以一种新型简便的低温酸化醚萃取法制备了一系列Keggin结构磷钼钨杂多酸催化剂,其结构和组成经FT-IR,XRD和XRF表征,并对其进行催化氧化脱硫性能研究。结果表明,控制酸化溶液pH、采用低的滴加温度是实现钼钨比可控、合成具备Keggin结构的磷钼钨杂多酸催化剂的关键。以双氧水为氧化剂,考察磷钼钨杂多酸催化剂对模拟汽油中的噻吩、苯并噻吩和二苯并噻吩的氧化性能。研究发现,随着杂多酸钼钨比的增加,催化氧化脱硫活性呈先增加后降低的趋势,其中H3PMo6.1W5.9O40杂多酸的催化氧化脱硫性能最优,对废机油裂解得到的汽柴油中噻吩类有机硫的完全转化时间为12h。

A series of phosphorus-molybdenum-tungsten heteropoly acid(HPA) catalysts with Keggin structure were prepared by a new and convenient low temperature acidification-ether extraction method. The structures and Mo/W ratio were characterized by FT-IT, XRD and XRF, and their catalytic oxidation desulfurization performance was studied. The results showed that pH of acidized solution and the low dropping temperature were key to synthesize the catalysts with the desired Mo/W ratio. Using hydrogen peroxide as the oxidant, octadearyl dimethyl ammonium chloride as a phase transfer catalyst, the catalytic performance in oxidation of thiophene, benzothiophene and dibenzothiophene in the simulated gasoline was investigated. It was found that the catalytic activity in oxidation desulfurization first increased and then decreased with the Mo/W ratio of HPAs increasing. H 3 PMO 6.1 W 5.9 O 40 exhibited the best catalytic oxidation performance in the desulfurization of the fuel oil from waste lube oil pyrolysis, sulfide compounds with thiophene structure can be converted completely in 12 h.