一步法制备含W介孔碳材料及其氧化脱硫性能研究

以钨酸钠为钨源,以乙二胺四乙酸二钠为碳源经过高温煅烧制备了含W的介孔碳材料,采用XRD、SEM、FT-IR、BET对含钨的介孔碳材料进行表征。结果表明,煅烧后介孔碳材料的表面形成了粒状含有结晶水的氧化钨(WO_3·H_2O)。相比于纯的介孔碳材料,含钨介孔碳材料的总比表面积减小。以含W介孔碳材料为催化剂,H_2O_2作为氧化剂,1-丁基-3-甲基咪唑氟硼酸盐(BMIM]BF_4])离子液体作为萃取剂,组成萃取-催化氧化脱硫体系(ECODS)并研究其对模拟油中二苯并噻吩脱除效果。考察了氧化钨负载量、反应温度、H_2O_2加入量、催化剂用量、离子液体用量以及不同类型硫化物对二苯并噻吩脱除的影响。在最佳反应条件下,催化剂对二苯并噻吩(DBT)、4,6-二甲基二苯并噻吩(4,6-DMDBT)、苯并噻吩(BT)、噻吩(TH)和真实汽油的脱除率分别达到98.6%、65.6%、61.2%、57.8%和64.3%。催化剂回收利用五次之后脱硫率略有降低,仍高达95.2%。

One-step preparation of mesoporous carbon containing tungsten and its desulfurization performance

A mesoporous carbon containing tungsten was prepared using Na₂WO₄ and EDTA-2Na as the source of tungsten and carbon and characterized by XRD, FT-IR, SEM and BET. The results show that the tungsten oxide with crystal water (WO₃·H₂O) is formed on the surface of mesoporous carbon. Compared with pure mesoporous carbon, the total surface area of mesoporous carbon containing tungsten decreases. An extraction-catalytic oxidation desulfurization (ECODS) system was constructed using mesoporous carbon containing tungsten as catalyst, H₂O₂ as oxidant and ionic liquids (ILs) 1-butyl-3-methyl imidazolium tetrafluoroborate (BMIM] BF₄]) as extraction agent. The effects of tungsten oxide loading, reaction temperature, the amount of H₂O₂, the amount of catalyst and ILs dosage and different types of sulfur compounds on the removal of DBT was studied. Under the optimal conditions, the removal rate of DBT reaches 98.6% for DBT, 65.6% for 4,6-DMDBT, 61.2% for BT, 57.8% for TH and 64.3% for actual gasoline, respectively. The desulfurization rate is slightly decreased when the catalyst is reused five times.