Design of stable Ni catalysts for partial oxidation of methane to synthesis gas

The supported Ni catalysts with CaAl₂O₄ spinel compound layer existed between Ni and Al₂O₃ have been prepared, and the effect of the CaAl₂O₄ spinel layer on the stability of the catalysts for the partial oxidation of methane to syngas (CO + H₂) has been investigated at high space velocity (250 L·g^-1·h^-1). Also, the catalysts have been characterized by XRD, TG/DTA. The Ni catalysts with CaAl₂O₄ spinel layer existed between Ni and Al₂O₃ show good stability for this process with the CH₄ conversion of ∼83%, syngas selectivity of >90% and the coke deposit of <1 wt% during a long-time running at 873 K. The CaAl₂O₄ spinel layer can effectively suppress the phase transformation to form NiAl₂O₄ spinel phases and stabilize the Ni tiny crystallite, to which the good stability of the catalyst contributes.