Nb-SBA-15的制备及催化氧化脱硫的研究

PREPARATION AND CATALYSTIC OXIDATIVE DESULFURIZATION OF Nb-SBA-15

以纯硅介孔分子筛SBA-15为载体,铌酸为铌源,采用后合成法制备了催化剂Nb-SBA-15,通过X射线衍射(XRD)、BET分析、差热分析对所制样品进行了表征。以异辛烷的二苯并噻吩溶液为模拟汽油,对介孔分子筛催化剂Nb-SBA-15的制备条件以及催化氧化脱硫性能进行了研究。实验结果表明,当铌酸负载量小于30%时,催化剂Nb-SBA-15仍具有规则的二维六方介孔结构。介孔分子筛催化剂Nb-SBA-15具有较高的催化活性和稳定性,在铌酸负载量为15%、催化剂焙烧温度为300℃、反应温度为60℃、反应时间为60 min、氧化剂H_2O_2与硫摩尔比为3、剂(N-甲基吡咯烷酮、NMP)油体积比为1、催化剂用量为5%时,脱硫率可达96.30%。

Post-synthesis method was adopted to prepare Nb-SBA-15 with mesoporous molecular sieve SBA-15 as carrier and niobic acid as niobium source. The samples were characterized by means of XRD, BET and DTA. The preparing condition of Nb-SBA-15 mesoporous molecular sieve catalyst and the oxidative desulfurization performance were studied by using iso-octane dibenzothiophene solution as simulated gasoline. The results indicated that Nb-SBA-15 catalyst could still keep ordered two-di-mensional hexagonal mesoporous molecular structure when the metal load of niobic acid was less than 30%. Nb-SBA-15 mesoporous molecular sieve catalyst has a better catalytic oxidative activity and sta-bility. The desulfurization rate could be up to 96.30% as the metal load of niobic acid was 15%, acti-vation temperature was 300 ℃, reaction temperature was 60 ℃, reaction time was 60 min, a molar ra tio of hydrogen peroxide to sulfur was 3, the volume ratio of solvent to oil was 1 and catalyst dosage was 5%（weight ratio）.