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本文利用动态热重法,结合程序升温还原等技术,研究了RE-Ni催化剂在正辛烷水蒸气转化反应中的抗积碳性能。研究发现,用共沉淀法和浸渍法制备的RE-Ni催化剂的抗积碳性均优于用同法制备的Ni催化剂,以共沉淀法效果更为明显。还发现RE-Ni催化剂抗积碳性能的改善与锻烧温度,还原条件及稀土氧化物含量有关。本文认为,在此反应过程中,稀土氧化物的抗积碳作用属氧化还原机理,水蒸汽在低价稀土氧化物表面上发生吸附解附解离,变低价RE~(m+)为高价RE~(n+)通过晶格氧向Ni表面的迁移,提高了Ni表面的氧浓度,达到抑制碳生成和加速碳消除的作用。
In this paper, using dynamic thermogravimetric method combined with temperature-programmed reduction technology to study the anti-carbon deposition performance of RE-Ni catalyst in n-octane steam reforming. The results show that the co-precipitation method and impregnation prepared RE-Ni catalyst anti-carbon deposition than the same method with the preparation of Ni catalyst to coprecipitation method effect is more obvious. It was also found that the improvement of the anti-carbon deposition performance of the RE-Ni catalyst is related to the calcination temperature, reduction conditions and the content of rare earth oxides. This paper argues that in the reaction process, the anti-carbonation effect of rare earth oxides is a redox mechanism, water vapor adsorption adsorption-desorption on the surface of low-cost rare earth oxides, variable low RE ~ (m + ~ (n +) through the lattice oxygen migration to the Ni surface, Ni surface oxygen concentration increased to achieve the role of inhibiting carbon generation and accelerate carbon elimination.