Pt-SO_(4)^(2-)/ZrO_(2)催化正丁烷异构化反应的性能

Catalytic performance of Pt-SO_(4)^(2-)/ZrO_(2) for n-Butane Isomerization

通过沉淀法和水热合成法制备了固体超强酸催化剂Pt-SO_(4)^(2-)/ZrO_(2),采用N_(2)吸附、X射线衍射(XRD)、吡啶红外光谱(Py-IR)、X射线光电子能谱(XPS)、高通量反应评价等技术对Pt-SO_(4)^(2-)/ZrO_(2)的结构、表面性质和正丁烷异构化性能进行了研究,并考察了反应条件对正丁烷异构化反应的影响规律。结果表明:与沉淀法制备的催化剂相比,水热法制得的催化剂具有更大的比表面积、孔体积和孔径,四方晶相氧化锆的晶相更加纯净且结晶度更高、硫含量更高、酸性更强、六价S的电子结合能更高,并且具有更高的正丁烷异构化活性;优化了水热法制备的Pt-SO_(4)^(2-)/ZrO_(2)催化剂催化正丁烷异构化反应条件,在反应温度190℃、压力1.8 MPa、正丁烷质量空速2 h^(-1)、氢/烃摩尔比0.1的条件下,正丁烷转化率和异丁烷选择性分别达到43.7%和86.4%。

Solid superacid based Pt-SO_(4)^(2-)/ZrO_(2) catalysts were prepared by both precipitation and hydrothermal synthesis methods.Catalysts were characterized by N_(2) adsorption,X-ray diffraction(XRD),pyridine infrared spectroscopy(Py-IR),X-ray photoelectron energy spectroscopy(XPS)and other technologies,and evaluated by high throughput screening for n-butane isomerization reaction.The structure,surface properties and n-butane isomerization performance of Pt-SO_(4)^(2-)/ZrO_(2) were studied,and the influence of reaction conditions on the catalytic performance in n-butane isomerization was investigated.Compared with the catalyst prepared by precipitation method,the catalyst prepared by hydrothermal method has larger specific surface area,pore volume and pore diameter.The crystal phase of tetragonal zirconia is of higher crystallinity.Besides,the catalyst prepared by hydrothermal method has higher sulfur content,stronger acidity,higher electron binding energy of hexavalent S,and higher n-butane isomerization activity.When the reaction temperature of 190℃,the pressure of 1.8 MPa,the mass hourly space velocity of n-butane of 2 h^(-1),and the hydrogen-to-hydrocarbon molar ratio of about 0.1,the solid superacid catalyst has the best isomerization activity.Under optimized conditions,the hydrothermal catalyst has better n-butane isomerization performance,with n-butane conversion of 43.7%and isobutane selectivity of 86.4%.