SiO2含量对Ni/SiO2-Al2O3催化剂上H2和O2等温吸附的影响

Effect of SiO2 Amounts in the Ni/SiO2-Al2O3 on the Isothermal Adsorption of H2 and O2

H2和O2吸附常用于金属催化剂的活性表面积、分散度、还原度和金属颗粒大小的测定.文章通过共沉淀制备不同SiO2含量的60%Ni/SiO2-Al2O3催化剂,并采用氢气和氧气的等温吸附进行表征.研究发现,随着SiO2含量的增加,催化剂的H2吸附量增大.SiO2的加入不仅有利于催化剂镍颗粒的还原,促进镍颗粒的分散,而且使得催化剂中金属镍的粒径显著减小,活性表面积显著增大.

The Ni/SiO2-Al2O3catalysts with different contents of SiO2 were prepared by co-precipitation meth. od and characterized by the isothermal adsorption of H2 and O2.The results showed that the H2 uptake of the catalysts was increased with the increase of SiO2 amount.The reducibility of metallic Ni in the catalysts was increased with the addition of SiO2 and the dispersion of Ni in the catalysts was enhanced.Thus,the particle sizes of metallic Ni in the catalysts were significantly decreased while the active areas of Ni were consider. ably increased with the increase of SiO2 content.