摘要
采用恒p H值共沉淀法和非恒p H值共沉淀法制备了Zn O-Zr O2混合氧化物催化剂,考察了制备方法对乙醇转化制异丁烯反应的影响,并用低温N2吸附、X射线衍射、扫描电子显微镜、透射电子显微镜、X射线光电子能谱、拉曼光谱、紫外-可见漫反射光谱、NH3程序升温脱附和CO2程序升温脱附对催化剂进行了表征。研究结果表明,相比于非恒p H值共沉淀法制备的Zn O-Zr O2,恒p H值共沉淀法制备的Zn O-Zr O2具有较高的比表面积,更多的酸量和碱量,从而表现出更好的乙醇转化制异丁烯催化性能。在450℃和乙醇质量空速0.2 h-1的反应条件下,两种催化剂的乙醇转化率均为100%,恒p H值共沉淀法制备的催化剂的异丁烯得率为54.9%,明显高于非恒p H值共沉淀法制备的催化剂(45.7%),并且稳定性也是前者明显高于后者。
ZnO-ZrO2 mixed oxide catalysts were prepared using either a constant or variable pH value co-precipitation method. The obtained catalyst samples were characterized using N2 adsorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, ultraviolet-visible diffuse reflectance, NH3 temperature-programmed desorption and CO2 temperature-programmed desorption. Compared to the ZnO-ZrO2 mixed oxide prepared using the variable pH value method, the corresponding mixed oxide prepared using the constant pH value method had a higher surface area and a higher number of acid sites and basic sites, thus exhibiting a superior catalytic performance. When the reaction temperature was 450℃ and the weight hourly space velocity of ethanol was 0.2 h-1, the conversion of ethanol for both catalysts was 100%. The ZnO-ZrO2 catalyst prepared using the constant pH value method gave 54.9% yield of isobutene, which was obviously greater than the yield obtained using the corresponding catalyst prepared using the variable pH value method （45.7%）. Moreover, the former catalyst exhibited obviously higher stability than the latter one for the isobutene production from ethanol conversion.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2016年第8期1391-1397,共7页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.21273043)
上海市科委资助项目(No.13DZ2275200)资助
关键词
混合氧化物
制备方法
乙醇
异丁烯
酸碱性
mixed oxide preparative method ethanol isobutene acidity and basicity
