载体对担载Ni催化剂甲烷与二氧化碳重整反应活性的影响

制备了 Zr O2 、Mg O改性的 Al2 O3、Ti O2 复合载体 ,并应用 X-射线粉末衍射 (XRD)、比表面积测定、扫描电镜 (SEM)等手段进行了表征 .结果表明 ,这些氧化物在 Al2 O3上的晶粒尺寸小、比表面积大 ,分散较好 ,而在Ti O2 上的分散性较差 .对经 10 73K焙烧的 Mg O/ Ti O2 ,还发现部分 Ti O2 载体由锐钛矿变为金红石 ,同时生成Mg Ti O3 新相 .考察了载体对 Ni催化剂的 CH4与 CO2 重整反应活性的影响 ,其次序为 :Mg O/ Al2 O3>Zr O2 /Al2 O3>Al2 O3>Mg O >Zr O2 >Ti O2 >Mg O/ Ti O2 . Ti O2 及 Mg O/ Ti O2 担载 Ni催化剂的低活性可能与 Ti O2 本身的还原性有关

Influences of Supports of Supported Ni Catalysts on Catalytic Performance in Carbon Dioxide Reforming of Methane

s: ZrO\-2\|, MgO\|modified Al\-2O\-3 and TiO\-2 supports were prepared. X\|ray diffraction (XRD) and scanning electron microscopy (SEM)techniques were used to study their structure. ZrO\-2/Al\-2O\-3 support has larger surface area and smaller particles sizes than ZrO\-2, which indicates a good dispersion on Al\-2O\-3 surface. Similar result is present on MgO/Al\-2O\-3. However, phase transformation from anatase to rutile took place and new MgTiO\-3 phase were formel in MgO/TiO\-2 support. Effects of the supports of supported Ni catalysts on the catalytic performances in CO\-2 reforming of CH\-4 were evaluated. The results indicate that Al\-2O\-3\|, MgO\|, ZrO\-2/Al\-2O\-3\|, and MgO/Al\-2O\-3\|supported Ni catalysts show high activities. On the contrary, TiO\-2\|, and MgO/TiO\-2\|supported Ni catalysts give very low activities. The order of CH\-4 conversion for various supported Ni catalysts is: Ni/MgO/Al\-2O\-3>Ni/ZrO\-2/Al\-2O\-3 > Ni/Al\-2O\-3 > Ni/MgO > Ni/ZrO\-2 > Ni/TiO\-2 > Ni/MgO/TiO\-2.