【摘要】 采用蒸氨法制备Cu/SiO₂催化剂,分别考察气相二氧化硅（SiO₂-aer）、硅胶（SiO₂-gel）和碱性硅溶胶（SiO₂-sol）对Cu/SiO₂催化剂催化甲醇裂解制氢性能的影响,并采用N2吸附-脱附、N2O化学吸附、电感耦合等离子体原子发射光谱法（ICP-AES）、X射线衍射（XRD）、H₂程序升温还原（H₂-TPR）、透射电子显微镜（TEM）和X射线光电子能谱（XPS）等方法对催化剂进行表征。结果表明,硅源对Cu/SiO₂催化剂的活性具有较大影响。以碱性硅溶胶作为硅源制得的Cu/SiO₂-sol催化剂比表面积较大,活性中心粒径较小且分散均匀,这些使得其制氢性能优于其他两种硅源为载体所制备的催化剂。在反应温度280℃,反应压力1 MPa,甲醇质量空速0.6 h-1的条件下,相较于Cu/SiO₂-aer和Cu/SiO₂-gel催化剂,Cu/SiO₂-sol催化剂的甲醇转化率分别提高10%和7%,气相副产物CH₄和CO₂浓度也有所降低,该催化剂上的甲醇转化率和气体收率分别达到98.4%和96.7%。更多还原

【Abstract】 Cu/SiO₂ catalysts were prepared via ammonia evaporation method,using fumed silica（ SiO₂-aer）,silica gel（ SiO₂-gel） and alkaline silica sol（ SiO₂-sol） as the silica sources and their catalytic performance in methanol decomposition were investigated. The catalysts were characterized by N₂ adsorption-desorption,N₂O chemisorption,inductively coupled plasma atomic emission spectroscopy（ ICP-AES）, X-ray diffraction（ XRD）,H₂ temperature programmed reduction（ H₂-TPR）,transmission electron microscope（ TEM） and X-ray photoelectron spectroscopy（ XPS）. The results indicate that silica source can affect the decomposition activity of Cu/SiO₂ catalysts. The Cu/SiO₂-sol catalyst prepared with alkaline silica sol exhibits larger surface area,smaller active site size and more uniform dispersion of Cu. Therefore,it gives Cu/SiO₂-sol a better decomposition performance than other catalysts. Methanol conversion on Cu/SiO₂-sol is 10% higher than that on Cu/SiO₂-aer,and 7% higher than that on Cu/SiO₂-gel. Additionally,byproducts concentration on Cu/SiO₂-sol is considerably lower than other catalysts. Under the reaction conditions of 280 ℃,1 MPa and 0. 6 h^-1 of WHSV,methanol conversion of 98.4% and gas yield of 96.7% can be achieved.更多还原