EFFECTS OF ALKALI AND RARE EATTH METAL OXIDES ON THE THERMAL STABILITY AND THE CARBON DEPOSITION OVER A NiO/Al_2O_3 CATALYST

采用固定床流动反应装置、ＣＯ吸附、ＴＧ、ＴＰＯ、ＸＰＳ和ＸＲＤ等手段考察了ＮｉＯ／Ａｌ２Ｏ３和ＬｉＮｉＬａＯ／Ａｌ２Ｏ３催化剂上的甲烷部分氧化反应。实验结果表明，ＬｉＮｉＬａＯ／Ａｌ２Ｏ３对甲烷部分氧化反应具有较高的反应活性。锂和镧的添加不仅改善了活性组分镍的分散度，而且提高了ＮｉＯ／Ａｌ２Ｏ３的抗积碳能力和热稳定性

EFFECTS OF ALKALI AND RARE EATTH METAL OXIDES ON THE THERMAL STABILITY AND THE CARBON DEPOSITION OVER A NiO/Al 2O3 CATALYST

The NiO/Al 2O 3 catalyst was modified by alkali metal oxide (Li, Na, K) and rare-earth metal oxide (La, Ce, Y, Sm) in order to improve the thermal stability and the ability of carbon-deposition resistance during the partial oxidation of methane (POM) to syngas reaction at high temperature. The reaction performance, thermal stability, dispersity of nickel and carbon-deposition of the modified NiO/Al 2O 3 catalyst and unmodified NiO/Al 2O 3 catalyst were investigated by a series of characterization techniques including flowreactor, CO chemisorption, TG, TPO, XPS and XRD. The results indicated that the modification with alkali metal oxide and rare earth metal oxide improved the dispersion of active component nickel and the activity for the POM reaction, and enhanced the thermal stability at high temperature and the ability to suppress the carbon-deposition over the nickel-based catalysts during the POM reaction.