超微粒介孔分子筛Ti-MC M-41的制备及催化氧化乙苯合成苯乙酮和α-苯乙醇

Preparation of Ultrafine Mesoporous Molecular Sieve Ti-MC M-41 and as Catalyst for Ethylbenene Oxidation to Synthesize Acetophenone and α-Phenylethyl Alcohol

在强酸性及常温常压下 ,以无水乙醇和异丙醇为混合溶剂 ,合成了n(Si)∶n(Ti)分别为 30∶1、5 0∶1和 70∶1的超微粒介孔分子筛Ti MCM 41。经X衍射光谱、Fourier红外光谱 (FTIR)和扫描电镜表征 ,该分子筛具有规则的晶体结构 ,颗粒直径为 0 0 5～ 0 1μm ,在FTIR的 96 0cm-1处表现出Si—O—Ti的特征吸收峰。同时研究了该分子筛在乙苯液相氧化中的催化行为 ,讨论了催化剂及反应条件的影响。结果表明 ,在Ti MCM 41催化下 ,双氧水可以将乙苯氧化为苯乙酮和α 苯乙醇。当催化剂n(Si)∶n(Ti)由 70∶1降至 30∶1,催化剂加入量由 10 0mg增加到 30 0mg ,n(H2 O2 )∶n(乙苯 )由 1 0∶1 0增至 3 0∶1 0 ,反应时间由 1h延长至 10h ,反应温度由 15℃升高到6 0℃时 ,乙苯的转化率分别提高到 3 3倍、1 4倍、2 6倍、1 7倍和 2 2倍。以氯仿、丙酮和甲醇为溶剂时 ,乙苯的转化率分别为 0 6 4%、1 2 7%和 3 5 5 %。

The ultrafine mesoporous molecular sieves Ti MCM 41 in which the molar ratio of silicate to titanium(Si/Ti) was 30∶1,50∶1 or 70∶1were prepared in strong acidic condition at room temperature and ambient pressure using mixed non aqueous solvent of ethyl alcohol and isopropanol.By characterization of X ray diffraction,Fourier transform infrared spectrum and scanning electron microscopy,the molecular sieves were proved to have regular crystal structures and the diameters were typically 0 05 to 0 1 μm.The absorption peak at 960 cm -1 in FTIR spectrum was the feature peak of Si-O-Ti bond in the molecular sieve.The catalytic behaviors of the molecular sieves Ti MCM 41 were studied in the oxidation of ethylbenene by hydrogen peroxide in which ethylbenene can be oxidized to acetophenone and α phenylethyl alcohol.Effects of parameters on the conversion and speed of ethylbenene oxidation were discussed in detail.When the molar ratios of Si to Ti in the catalyst decreased from 70∶1 to 30∶1,the added amount of catalyst rose from 100 mg to 300 mg,molar ratios of H 2O 2 to ethylbenene from 1 0∶1 to 3 0∶1,reaction time from 1 h to 10 h,and reaction temperature from 15 ℃ to 60 ℃,the conversion of ethylbenene would be raised 3 3 times,1 4 times,2 6 times,1 7 times and 2 2 times respectively.Using chloroform,acetone and methanol as solvent,the conversion of ethylbenene was 0 64%,1 27% and 3 55% respectively.