TiO_2促进纤维状碳基固体酸的制备及性能表征

Preparation and characterization of the fiberous carbon-based solid acid promoted by TiO_2

以TiO2负载的脱脂棉纤维为原料,通过碳化和磺化的方法制备了新型碳基固体酸催化剂(Ti/CS).利用扫描电镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、N2物理吸附(BET)、化学吸附(NH3-TPD)、元素分析(EA)等方法对催化剂进行了结构表征,并评价了催化剂在乙酸和乙醇酯化反应和淀粉水解反应中的催化活性.结果表明,TiO2以锐钛矿的形式负载于催化剂表面,同时酸性与无TiO2负载的碳基固体酸(CS)相比有所增强.酯化反应中,乙酸的转化率为85%,乙酸乙酯的产率为81%;淀粉水解反应中,120℃微波辐射40min,葡萄糖收率最高可达86%。

The new sulfonated carbon-based solid acid catalysts（Ti/CS）were prepared by the carbonization and sulfonation of cotton fiber coated by TiO2under different temperatures.The as-synthesized catalysts were characterized by the scanning electron microscopy（SEM）,X-ray diffraction（XRD）,fourier transform infrared spectroscopy（FT-IR）,nitrogen physisorption（BET）,NH3temperature-programmed desorption（NH3-TPD）,and elemental analysis（EA）.Results showed that TiO2exited as the phase of anatase on the surface of catalysts,which strongly enhanced the acidity compared with the catalysts without TiO2loading.Two typical reactions of hydrolysis and esterification were also investigated to evaluate their catalytic performances.In the esterification reaction catalyzed by Ti/CS-140,the conversion of acetic acid reached as high as 85%and the yield of ethyl acetate could reach 81%.In the hydrolysis reaction,the yield of glucose could reach to 86% by holding 40min at 120℃ under microwave irradiation.