介孔SBA-16负载Nb_(2)O_(5)光催化脱硫催化剂

Mesoporous SBA-16 supported Nb_(2)O_(5) photocatalytic desulfurization catalyst

采用浸渍法制备了Nb_(2)O_(5)/SBA-16催化剂,利用XRD、FTIR、N_(2)吸附-脱附、UV-Vis、SEM、TEM、XRF等方法分析了催化剂结构和性质。以含二苯并噻吩的十二烷溶液为模拟油,分别以30%(w)H_(2)O_(2)和甲醇为氧化剂和萃取剂,考察了催化剂的光催化氧化脱硫性能,优化了工艺条件并提出了催化机理。实验结果表明,Nb_(2)O_(5)/SBA-16催化剂保持了高度有序的介孔结构,且比表面积高、活性组分分散均匀;反应符合一级动力学;选择20%(w)Nb_(2)O_(5)/SBA-16催化剂,当催化剂用量1%(w)、O/S摩尔比10∶1、萃取剂与模拟油体积比1∶1时,脱硫效果最佳,脱硫率达98.06%,循环6次后仍有较高脱硫率;反应的主要活性中间物种为超氧自由基和空穴。

Nb_(2)O_(5)/SBA-16 catalyst was prepared with impregnation method,and the structure and properties of the catalyst were characterized by XRD,FTIR,N_(2) adsorption-desorption,UV-Vis,SEM,TEM,and XRF.The photocatalytic oxidative desulfurization activity of the catalyst was investigated using dodecane solution containing dibenzothiophene as the simulated oil,30%(w)H_(2)O_(2) and methanol as the oxidant and the extractant respectively.The process conditions were optimized and the catalytic mechanism was proposed.The experimental results show that Nb_(2)O_(5)/SBA-16 catalyst maintains a highly ordered mesoporous structure with high specific surface area and uniform dispersion of active components.The reaction follows first-order kinetics.When 20%(w)Nb_(2)O_(5)/SBA-16 is used as catalyst,the catalyst amount is 1%(w),the O/S molar ratio is 10∶1,and the volume ratio of extractant to simulated oil is 1∶1,the best desulfurization rate is 98.06%,and is still high after 6 cycles.The main active intermediate species in the reaction are superoxide radicals and holes.