Highly selective synthesis of para-diethylbenzene by alkylation of ethylbenzene with diethyl carbonate over boron oxide modified HZSM-5
Highly selective synthesis of para-diethylbenzene by alkylation of ethylbenzene with diethyl carbonate over boron oxide modified HZSM-5
复制标题
DOI：
10.1016/j.molcata.2014.08.046
复制
发表时间：
2014-12
影响因子：
--
通讯作者：
Bing Xue;Genlei Zhang;Liu Na;Jie Xu;Qingming Shen;Yong-Xin Li
中科院分区：
文献类型：
--
作者：
Bing Xue;Genlei Zhang;Liu Na;Jie Xu;Qingming Shen;Yong-Xin Li
采用硼酸三乙酯、硼酸三甲酯和硼酸浸渍HZSM-5分子筛，制备了一系列B2O3/HZSM-5催化剂。采用B2O3/HZSM-5催化剂，对乙苯与碳酸二乙酯的烷基化反应进行了选择性合成对二乙苯的研究。采用x射线衍射、n2吸附-脱附、吡啶吸附傅立叶变换红外光谱和nh3程序升温脱附等手段对催化剂的理化性质进行了表征。表征结果表明，以硼酸三乙酯为前驱体制备的15% B2O3/HZSM-5催化剂在乙苯与碳酸二乙酯的烷基化反应中具有良好的形状选择性和较高的催化活性。这可能是由于硼酸三乙酯的大分子尺寸导致b2o3在HZSM-5沸石的外表面形成，并保留了微孔中的酸位。而硼酸三甲酯或硼酸制备的B2O3/HZSM-5催化剂的催化活性则严重降低，这是由于HZSM-5分子筛的部分孔被堵塞导致总酸位数量减少所致。
A series of B2O3/HZSM-5 catalysts were prepared by impregnation of HZSM-5 zeolites with triethyl borate, trimethyl borate and boric acid. The selective synthesis ofpara-diethylbenzene by alkylation of ethylbenzene with diethyl carbonate was carried out over the B2O3/HZSM-5 catalysts. The physicochemical properties of the catalysts were characterized by X-ray diffraction, N2adsorption–desorption, Fourier-transform infrared spectroscopy with pyridine adsorption and NH3temperature programmed desorption. The characterization results indicated that the 15% B2O3/HZSM-5 catalyst prepared by using triethyl borate as the precursor exhibited an outstanding shape-selectivity along with a high catalytic activity in alkylation of ethylbenzene with diethyl carbonate. This might be ascribed to the large molecular size of triethyl borate, which would lead to the formation of B2O3on the external surface of HZSM-5 zeolite and preserve the acid sites in the micropores of HZSM-5 zeolite. By contrast, the B2O3/HZSM-5 catalysts prepared by using trimethyl borate or boric acid led to the severe reduction in catalytic activity, which was attributed to the decrease in the amount of the total acid sites caused by the blockage of the partial pores of HZSM-5 zeolite.