Preparation of activated carbon supported Fe-Al_2O_3 catalyst and its application for hydrogen production by catalytic methane decomposition

摘要

Activated carbon (AC) supported Fe-Al_2O_3 catalysts were prepared by impregnation method and used for catalytic methane decomposition to hydrogen. The XRD and H_2-TPR results showed that ferric nitrate on AC support was directly reduced to Fe metal by the reducibility of carbon at 870 ℃. The loading amount and Fe/Al_2O_3 weight ratio affect the textural properties and catalytic methane decomposition. The surface area and pore volume of the catalyst decrease with the loading of Fe and Al_2O_3. Mesopores with size of about 4.5 nm can be formed at the loading of 20-60% and promote the catalytic activity and stability. The mesopores formation is thought that Fe accelerates burning off of carbon wall and enlarging pore sizes during the pretreatment. When the Fe/Al_2O_3 ratio is 16/24 to 24/16 at the loading of 40%, the resultant catalysts show narrow mesopore distributions and relative high methane conversion. Al_2O_3 as the promoter can improve catalytic activity and shorten transitional period of AC supported Fe catalyst.