Preparation of Ni/12CaO⋅7Al2O3 honeycomb-type catalyst for continuous production of hydrogen by methane decomposition

Abstract

• 12CaO⋅7Al 2 O 3 was firmly coated on a honeycomb-type cordierite ceramic support via a hydration reaction process. • The surface state of 12CaO⋅7Al 2 O 3 was an important factor for the combustion activity as a cocatalyst. • Hydrogen production by methane decomposition using the prepared 12CaO⋅7Al 2 O 3 honeycomb-type catalyst was performed under a practical condition (SV: 2000 h −1 ) with water vapor, and the hydrogen concentration of ca.15% was continuously achieved. The mixed oxide 12CaO⋅7Al 2 O 3 was firmly coated onto a honeycomb-type cordierite ceramic support via calcium aluminate hydroxides generated by a reaction with water. The crystal structure of this material, which was collapsed as a result of the reaction with water, was restored by subsequent recalcination. The 12CaO⋅7Al 2 O 3 was found to promote the combustion of an organic compound (ethanol), and this activity was expected to reduce the accumulation of carbon residue on the catalyst surface during methane decomposition. The surface state of the 12CaO⋅7Al 2 O 3 was determined to be an important factor related to its combustion activity, as were the specific surface area and crystallinity of the material. Continuous hydrogen production via methane decomposition was demonstrated using the 12CaO⋅7Al 2 O 3 honeycomb-type catalyst loaded with Ni under practical conditions (including a space velocity of 2000 h −1 ) in the presence of water vapor.