H_5PMo_(10)V_2O_(40)/SBA-15催化剂的制备及其催化性能

Preparation and Catalytic Properties of H_5PMo_(10)V_2O_(40)/SBA-15 Catalyst

以Keggin型杂多酸H5PMo10V2O40为主体,SBA-15介孔分子筛为载体,利用溶胶-凝胶法制备了不同负载量的H5PMo10V2O40/SBA-15负载型催化剂,通过XRD、FTIR、TEM、H2-TPR和N2吸脱附法对样品进行了分析和表征,并将制得的负载型催化剂应用于苯氧化苯酚的反应中,研究了不同条件(温度、时间和催化剂用量等)下的催化性能。研究结果表明:H5PMo10V2O40杂多酸能均匀地分散于SBA-15孔道中且SBA-15的六方介孔结构并未发生改变;较好地解决了活性组分大量溶脱的问题;与H5PMo10V2O40杂多酸相比,H5PMo10V2O40/SBA-15催化剂在苯氧化为苯酚的反应中具有更高的转化率和更好的选择性,当反应温度为70℃,催化剂的使用量为0.25 g,反应时间为2 h和H5PMo10V2O40负载量为60%时苯酚的选择性达到了82.53%。

Based on Keggin heteropolyacid（H5PMo10V2O40） as host and the mesoporous molecular sieve（SBA-15） as a carrier, a catalyst （H5PMo10V2O40/SBA-15） with the different amount of H5PMo10V2O40 was prepared using sol-gel process. The structure and properties of the catalyst were characterized by XRD, FTIR, TEM, H2-TPR and N2 adsorption-desorption. The H5PMol0V2O40/SBA-15 can be applied for the oxidation reaction of benzene. The catalytic reaction was investigated under different conditions, such as temperature, reaction time, amount of catalyst, etc. As results of experiment, H5PMo10V2O40 was highly dispersed on the SBA-15 of which the structure was not changed, in addition, huge amounts of desolventing was limited during the reaction. Compared with H5PMo10V2O40 the H5PMo10V2O40/SBA-15 showed much higher selectivity and conversion from benzene to phenol. When the amount of catalyst was 0.25 g and its loading was 60%, the selectivity was up to 82.53% at 70 ℃ for 2 h.