Mesoporous NiO-Al₂O₃ catalyst for high pressure partial oxidation of methane to syngas

Mesoporous NiO-Al₂O₃ catalysts were applied to catalytic partial oxidation of methane at 650 °C, 1 MPa with a feed composition of CH₄/O₂/N₂/Ar = 5.2 vol.%/2.6 vol.%/4.9 vol.%/balance. In order to investigate the effect of mesopore of the catalyst on the catalytic activity, we used various types of organic reagents, such as P123, F127, PEG6000, and some carboxylic acids, to prepare bulk NiO-Al₂O₃ catalysts. Among the organic reagents P123, F127, and PEG6000 were effective for the formation of mesopores. As a result of activity tests, the catalyst prepared by using P123 showed the highest oxidative activity and selectivity; the values were higher than those of NiO catalyst supported on α-Al₂O₃ or γ-Al₂O ₃. Results of pulse reaction indicated that the oxidation tolerance of NiO-Al₂O₃ prepared with P123 was high under reaction conditions. The effect of pore size of the catalyst was predominant because in the mesopores the diffusion values of the reactant gases are different and the CH₄/O₂ ratio in the pores was kept high. These factors contributed to the high selectivity of the mesoporous NiO-Al₂O ₃ catalysts.