甲烷转化催化剂的水吸附脱附性能

Adsorption and desorption of methane on steam re-forming catalysts

采用脉冲吸附和程序升温脱附法考察了镍转化催化剂的水吸附和热脱附性能。试验发现,在吸附水初期,水发生解离放出氢,随吸附次数增加,解离吸附下降很快。热脱附时,脱附物中未发现氢。水在催化剂载体上吸附较弱,低温即脱附,在镍表面吸附较强,>300℃才开始脱附。在催化剂中添加稀土助剂后,水吸附量增大:120℃吸附时,约大17%;600℃时,则大4.9倍。其吸附水量的大小与其抗积炭性能好坏相一致。

The adsorption and heat desorption performances of wator on nickel reforming catalysts were determined by pulsed adsorption and TPD process. It has been found that water is decomposed to give hydrogen at the early period of adsorption. The decomposition adsorption decreases rapidly with the increase of adsorption times. When heat desorption takes place.no hydrogen is found in the desorbate. Water is adsorbed weakly on the catalyst support,while it is desorbed at low temperature. Water is adsorbed strongly on the nickel surface and it is desorbed at the temperature more than 300℃. After adding rare—earth into the catalyst as a promoter, the adsorbed water quantity increases. The water adsorbed is increased by about 17% when the adsorption takes place at 120℃ and it is more than 4. 9 times at 600℃. The adsorbed water quantity is consistent with the catalyst performance against carbon deposit.