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利用接枝方式将2,2,6,6-四甲基哌啶(TEMPO)固载到SPE柱填料硅胶上制备了功能化硅胶,其吸附NOx应用于催化醇的选择性氧化反应中.并利用元素分析、红外光谱、N2吸附-脱附和NOx程序升温脱附对催化剂进行了考察.结果表明,所制备催化剂中TEMPO固载量为0.292 mmol/g,NOx吸附量为0.749 mmol/g;常温常压下1 mmol芳香醇在0.5 g该催化剂作用下进行选择性氧化反应2 h,原料转化率和产物选择性均高达99%.该催化剂提高了醇分子在孔道内部与TEMPO和NOx接触几率,促进了反应进行,根据反应现象,对该体系催化机理进行了推测.
The functionalized silica gel was prepared by immobilizing 2,2,6,6-tetramethylpiperidine (TEMPO) onto the silica gel of SPE column by grafting method, which adsorbed NOx to catalyze the selective oxidation of alcohol. The catalysts were investigated by elemental analysis, infrared spectroscopy, N2 adsorption-desorption and NOx temperature-programmed desorption. The results showed that the TEMPO loading was 0.292 mmol / g and the NO x adsorption capacity was 0.749 mmol / g. Under normal pressure, 1 mmol of aromatic alcohol was oxidized for 2 h under the action of 0.5 g of catalyst, the conversion of raw materials and product selectivity were as high as 99% .The catalyst increased the contact probability of alcohol molecule with TEMPO and NOx inside the pore, Promote the reaction, according to the reaction phenomenon, the catalytic mechanism of the system was speculated.