添加剂MgO和La_2O_3对甲烷化镍催化剂的影响

本文采用XRD相定量法测定了NiO和MgO在Al_2O_3表面的单层分散容量,并研究甲烷化催化剂中添加剂MgO和La_2O_3对NiO分散容量的影响。用H_2还原法研究Ai_2O_3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La_2O_3能增加NiO在Al_2O_3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。

Effect of MgO and La_2O_3 Additives Ni Methanation Catalyst

XRD was employed to determine monolayer dispersion capacities of NiO and MgO on Al_2O_3 surface in methanation catalysts. The effect of MgO and La_2O_3 additives on NiO dispersion capacity was studied. Reducibility of NiO on Al_2O_3 Surface by H_2 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 La_2O_3 increased the monolayer dispersion capacity of NiO on Al_2O_3, 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.