含鎳金屬担體觸媒的研究第三報　沉澱法觸媒在CO甲烷化反應中之活性與熱穩定性

Study on Supported Nickel Catalysts, III Activity and Thermal Stability of Precipitated Catalysis in CO Methanation

葉石川(S. C. Yeh) ； 沈世宏(S. H. Shen) ； 李敏達(M. D. Lee)

《化學》 42卷1期 (1984/03) Pp. 38-50

https://doi.org/10.6623/chem.1984005

摘要

利用三種沈澱法製造N_1／Al_2O_3觸媒，將其應用於一氧化碳之甲烷化反應，以探討觸媒活性與熱穩定性。由觸媒之規劃升溫還原試驗得知，沈澱法所製成之觸媒，活性表面積大而粒徑小，在高鎳含量下尚可保持良好之分散狀態。還原度則與含浸法觸媒相差不大。甲烷化反應之溫度低於210℃時，均勻沈澱法與共沈澱法觸媒具有最佳之初期活法。燒結觸媒之活性試驗顯示，均勻沈澱法及共沈澱法觸媒呈現良好之熱穩定性。沈澱固著法觸媒在高溫氫氣流下燒結後，因還原晶粒之成長及新晶粒之產生，活性反而有提升之現象。

並列摘要

The N_1 catalysts supported on Al_2O_3 were preapred by different precipitation methods and their catalytic activity and thermal stability were examined toward Co methanation. The temperature- programmed reduction studies showed that the precipitated catalysts were possessed of large active surface area, small particle size, and, even at high Ni loading, good dispersion. There was no appreciable difference in the degree of reduction between the precipitated catalysts and the impregnated catalysts. Homogeneous precipitation and precipitative occlusion gave the catalysts with higher initial activity in the CO methanation at reaction temperature below 210°C. In the activity tests for sinterred catalysts, homogeneous precipitation and coprecipitation catalysts were found to have excellent thermal stability. The increase in the activity of precipitative occlusion catalysts after sinterring at higher temperature and hydrogen stream may be due to the growth of reduced crystals and the formation of new crystals.