Reforming of methane with carbon dioxide over cerium oxide promoted nickel nanoparticles deposited on 4-channel hollow fibers by atomic layer deposition

Abstract

Ni nanoparticles were deposited on four-channel structured α-Al₂O₃ hollow fibers by atomic layer deposition (ALD). CeO₂ was loaded by a liquid phase incipient wetness method to promote Ni catalysts for dry reforming of methane. For Ni/Al₂O₃ prepared by ALD, inactive NiAl₂O₄ that originated from the Ni ALD process was incompletely reduced. The introduced CeO₂ was found to weaken the NiO–Al₂O₃ interaction, free NiO from NiO–Al₂O₃ or NiAl₂O₄, and improve the reducibility of NiO. The higher reducibility of NiAl₂O₄, tuned by CeO₂, further activated the catalyst during DRM, because a larger proportion of NiAl₂O₄ was gradually reduced to metallic nickel by the reaction products. The optimal catalytic performance reached a methane reforming rate of 2410 L h⁻¹ g_Ni⁻¹ at 850 °C. The CeO₂ promoted catalyst also exhibited an excellent performance after regeneration. In addition, the inhibition effect of CeO₂ on coke formation was observed, due to the enhanced CO₂ dissociative adsorption by CeO₂.