【摘要】 本文采用XRD相定量法测定了NiO和MgO在Al₂O₃表面的单层分散容量,并研究甲烷化催化剂中添加剂MgO和La₂O₃对NiO分散容量的影响。用H₂还原法研究Ai₂O₃表面上的NiO的还原性能,以及添加剂对NiO还原性能和还原后Ni晶粒大小的影响。试验结果表明,单层分散的NiO要比晶相NiO难还原。适量的MgO和La₂O₃能增加NiO在Al₂O₃上的单层分散容量,并使还原得到的Ni晶粒变小。但MgO的加入量过高会降低NiO的还原度。更多还原

【Abstract】 XRD was employed to determine monolayer dispersion capacities of NiO and MgO on Al₂O₃ surface in methanation catalysts. The effect of MgO and La₂O₃ additives on NiO dispersion capacity was studied. Reducibility of NiO on Al₂O₃ Surface by H₂ flow and effect of the additives on reducibility of NiO, as well as crystal size of the reduced nickel were also investigated. Experiments show that crystalline NiO was more easily reducible than dispersed NiO monolayer. Proper addition of MgO and La₂O₃ increased the monolayer dispersion capacity of NiO on Al₂O₃, and caused the crystal size of nickel to become smaller. However, the extent of reduction of NiO would decrease, if an excess of NgO was added.更多还原