Cs取代对Ni-H_3PW_(12)O_(40)/SiO_2催化剂结构性质和催化性能的影响（英文）

Abstract

采用两步浸渍法和载体上的原位反应制备了一系列CS部分取代的nI-CSX H3-X PW12O40/SIO2催化剂,并用n2吸附比表面积测定(bET)、电感耦合等离子体发射光谱(ICP)、X射线衍射(Xrd)、拉曼光谱(rAMAn)、原位X射线衍射(In SITu Xrd)、nH3程序升温脱附(nH3-TPd)、H2程序升温还原(H2-TPr)、H2程序升温脱附(H2-TPd)、吡啶吸附傅里叶变换红外(fTIr)光谱等分析测试技术对催化剂进行了表征.以正癸烷为模型化合物,对催化剂的加氢裂化性能进行了评价.结果表明,8%nI-50%CS1.5H1.5PW/SIO2催化剂具有最高的C5+收率,明显优于8%nI-50%H3PW/SIO2催化剂和工业催化剂.随着CS在CSX H3-X PW中比例的增加,正癸烷的转化率逐渐降低,而C5+选择性则逐渐提高.当催化剂具有合适的孔径时,选择性的提高是由于催化剂酸性的减弱,而转化率的降低则是由于催化剂加氢能力的减弱.

Cs-substituted Ni-Csx H3-x PW12O40/SiO2catalysts were prepared by two-step impregnation and in situ reaction on the support.The catalysts were characterized by N2adsorption measurements,inductively coupled plasma atomic emission spectrometry,Raman spectroscopy,in situ X-ray diffraction,NH3-temperature programmed desorption(TPD),H2-temperature programmed reduction,H2-TPD,and Fourier transform infrared spectroscopy.The hydrocracking of n-decane was used to study the catalytic performance of the Ni-Csx H3-x PW12O40/SiO2catalysts.The highest C5+yield obtained for 8%Ni-50%Cs1.5H1.5PW/SiO2was superior to those of 8%Ni-50%H3PW/SiO2and an industrial catalyst.The conversion of n-decane slightly decreased and the C5+selectivity increased with increasing Cs content in the Csx H3-x PW catalysts.Ni-Csx H3-x PW12O40/SiO2catalysts possessed relatively large pore sizes,so the improved selectivity might have been due to a weaker acidity of the catalysts.The reduced conversion might have been due to a weaker hydrogenation ability.