镍基催化剂上乙醇水蒸气重整反应的研究

Ethanol steam reforming over supported Ni catalysts

考察了载体对N i催化剂乙醇水蒸气重整制氢反应性能的影响。结果表明,N i/CeO2催化剂具有较好的低温活性和氢气选择性。对N i担载量和焙烧温度考察发现,400℃焙烧的15%N iCeO2催化剂具有较好的催化性能;继续升高焙烧温度引起N iO和CeO2粒子的显著增大,导致对氢气选择性的降低。较小的N i和CeO2粒子有利于乙醇水汽重整反应的进行,而大的粒子倾向于乙醇的分解反应。350℃时,在反应过程中分别添加CO、CO2和CH4的结果表明没有发生CO和CO2甲烷化反应,而发生了一定程度的CH4水汽重整反应。

Hydrogen production from ethanol steam respect to the nature of the support, the metal loading reforming has been investigated over nickel catalysts with and calcination temperature. It was found that the Ni/CeO2 catalyst with Ni loading of 15 % is more active and selective toward hydrogen production. Increasing the calcination temperature results in the agglomeration of NiO and CeO2 particles, and consequently decreases the reforming ability of the catalyst. Namely, smaller particles favor the ethanol steam reforming, while larger NiO and CeO2 particles promote the decomposition of ethanol. Mechanistic study by adding CO, CO2 and CH4 to the reaction stream at 350℃ further suggests that methane is produced by the direct decomposition of ethanol and/or acetaldehyde, instead of the methanation reactions of CO and CO2.