氧化镍/莫来石-刚玉催化剂中添加La2O3的作用

用ＸＲＤ，ＴＰＲ，ＴＧ－ＤＴＡ考察了氧化镍／莫来石－刚玉催化剂添加Ｌａ２Ｏ３对ＮｉＯ性质的影响及两者间的相互作用，Ｌａ２Ｏ３使得催化剂中ＮｉＯ的晶格常数及分散容量增大，而晶相含量减少，还发现，添加Ｌａ２Ｏ３，使一次ＴＰＲ过程中ＮｉＯ还原温度升高，耗氢量增加了Ｌａ２Ｏ３对二次ＴＰＲ中ＮｉＯ还原温度的影响减小，耗氢量不受影响，Ｌａ２Ｏ３的添加方式及含量不同，对ＮｉＯ性质的影响也不相同。

STUDY OF THE EFFECT OF La 2O 3 ON NiO/MULLITE CORUNDUM CATALYST

NiO/M C (NiO/mullite corundum) and La 2O 3 promoted NiO/M C catalysts for hydrocarbon steam reforming were investigated by XRD, TPR and TG DTA. The experimental results indicated that La 2O 3 could cause the increase of the lattice constants of NiO and improve the dispersion of NiO and Ni, thus reduced the amount of crystalline NiO and Ni. During the first TPR, increasing the La content led to a higher reduction temperature for NiO and an enhanced H 2 consumption. While in the second TPR, the peak temperature of NiO did not change with La content and the H 2 consumption was always close to n (H)/ n (Ni)=2. The higher H 2 consumption in the first TPR might be caused by partial reduction of La 2O 3, which was due to the intimate contact between NiO and La 2O 3. The effect of La 2O 3 on the properties of NiO and the interaction between them were different with different preparation methods and La 2O 3 amounts in the catalyst.