Abstract:
A series of Ni-based catalysts with different supports (Al
2O
3, ZrO
2, CeO
2, CeO
2-Al
2O
3 and ZrO
2-Al
2O
3) were prepared by the methods of impregnation. The effects of supports on the physical structures and catalytic performance of the resultant catalysts in partial oxidation of methane (POM) were investigated. The catalysts were characterized by N
2 physical adsorption, X-ray diffraction, temperature programmed reduction by hydrogen, temperature programmed desorption of ammonia and temperature programmed oxidation. The results showed that the Ni/Al
2O
3 catalyst had a large BET specific surface area and high initial activity. However, the Ni/Al
2O
3 catalyst showed a serious deactivation due to the formation of large amount of carbon deposited on the surface of the catalyst. Ni/ZrO
2 and Ni/CeO
2 catalysts displayed low activity, which resulted from its low BET specific surface area and poor NiO dispersion. The Ni/ZrO
2-Al
2O
3 catalyst showed high activity and the Ni/CeO
2-Al
2O
3 catalyst exhibited the best activity and coking resistance among the catalysts. CeO
2 could effectively suppress carbon formation and the transformation to inactive carbon species, due to the oxygen storage and release ability.