程序升温甲烷裂解反应的研究

Study on the temperature programmed cracking reaction of methane

本文介绍用程序升温表面裂解反应技术研究甲烷在不同载体及不同添加助剂的镍催化剂上的裂解行为。试验表明:甲烷在无活性组份的载体上,1000℃以下裂解很少;在镍催化剂上,350℃即可进行裂解。由于裂解生成的炭复盖了催化剂上的活性中心,随着温度的升高,裂解曲线呈峰形分布。甲烷裂解活性随着镍晶粒度的减小而升高。采用先浸渍镍,后载上重稀土混合氧化物的镍催化剂可明显降低甲烷裂解速度。

The decomposition of methane on the different supports, Ni-catalysts and Ni-catalysts with the addition of RE_2O_3 (heavier rare-earth oxides) was investigated by use of the temperature programmed cracking reaction(TPCR). The results showed that the cracking of CH_4 was minor on the supports at the temperature be■ow 1000℃ and might take place at 350℃ on the Ni-catalyst. The change of cracking rate of CH_4 with the increase of reaction emperatiire exhibited a peak type curve because the active centers on the catalyst were covered by the cracked carbon. The activity of the catalyst for CH_4 cracking was increased with the decrease of its Ni-crystaiiite size. The cracking rate of CH_4 was reduced obviously on the catalyst prepared by the addition of NiO prior to ER_2O_3.