HPW/HY-SBA-15催化剂的制备及氧化脱硫性能研究

采用后合成法合成了HY-SBA-15复合分子筛,并以其为载体,负载不同比例的磷钨酸(HPW)制备催化剂.用XRD对HY-SBA-15复合分子筛及HPW/HY-SBA-15催化剂进行了表征,结果表明:适量磷钨酸的引入并没有改变复合分子筛的介孔结构,但会使其衍射峰的强度有所降低.以硫含量为500 μg/g模拟油进行氧化脱硫反应,考察了反应温度、反应时间、磷钨酸负载比例、剂油比、氧化剂用量等工艺条件对脱硫率的影响.研究结果表明:磷钨酸的负载量为20％(质量分数),活化温度为300℃时的HPW/HY-SBA- 15催化剂效果最好,在模拟油用量为30 mL,反应温度50 ℃,反应时间90 min,剂油比(催化剂与模拟油的质量比)为0.02,n(H2O2)∶n(S)=8,无水乙醇用量3 mL的条件下,脱硫率可达95.7％.

Preparation and Oxidation Desulfurization Performance of HPW/HY-SBA-15 Catalyst

Under the hydrothermal condition,the HY-SBA-15 composite molecular sieve was prepared by post-synthesis method.Then HPW/HY-SBA-15 catalyst was prepared by loading different proportions of phosphotungstic acid(HPWA) on the sieve,and the HY-SBA-15 composite molecular sieve and HPW/HY-SBA-15 catalyst were characterized by XRD.The results show that appropriate amount of phosphotungstic acid can not change mesoporous structure of the composite molecular sieve,but can decrease the intensity of diffraction peaks.The catalyst was tested by model oil with 500 μg/g sulfur.The influence of reaction temperature,reaction time,different loading proportions of phosphorustungsten acid(HPWA),ratio of catalyst to oil and oxidant dosage on oxidative desulfurization of the model oil was investigated.The results show that when loading of phosphotungstic acid(mass fraction) is 20% and activation temperature is 300 ℃,HPW/HY-SBA-15 catalyst can get the best desulfurization rate.When the model oil is 30 mL,reaction temperature is 50 ℃,reaction time is 90 min,ratio of catalyst to oil is 0.02, n(H202)∶n(S) = 8,amount of ethanol is 3 mL,the desulfurization rate can reach to 95.7%.