摘要
H_2和O_2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SiO_2含量的60%Ni/SiO_2-Al_2O_3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SiO_2含量的增加,催化剂的H_2吸附量增大.SiO_2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/SiO_2-Al_2O_3catalysts with different contents of SiO_2were prepared by co-precipitation method and characterized by the isothermal adsorption of H_2and O_2.The results showed that the H_2uptake of the catalysts was increased with the increase of SiO_2amount.The reducibility of metallic Ni in the catalysts was increased with the addition of SiO_2and 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 considerably increased with the increase of SiO_2content.
引文
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