Preparation of egg-shell type Ni-loaded catalyst by adopting 'memory effect' of Mg-All hydrotalcite and its application for CH_4 reforming

摘要

Ni-loaded catalyst in egg-shell type was successfully prepared by adopting "Memory Effect" of Mg-Al hydrotalcite-like compounds.Mg-Al mixed oxide particles were prepared by calcination of Mg-Al hydrotalcite and dipped in Ni(II) nitrate aqueous solution.Upon dipping,Mg-Al hydrotalcite was reconstituted in the surface layer of the particle and a part of the Mg sites was replaced by Ni.Finally egg-shell type loaded Ni catalyst was obtained after the calcination followed by the reduction of the particles.The catalyst showed a high and stable activity for autothermal CH_4 reforming due to highly dispersed and stable Ni metal particles concentrated in the catalyst surface layer.