In this work, a ceria promoted Ni-based catalyst supported in mesoporous montmorillonite (MMT) was developed and evaluated in ethanol steam reforming. This Ni-Ce/MMT catalyst was synthesized by an ultrasound assisted cation exchange impregnation method and characterized by X-ray diffraction, N-2 adsorption desorption, H-2 temperature-programmed reduction and transmission electron microscopy. TEM images of Ni-Ce/MMT presented that narrow Ni nanoparticles (ay. 6.0 nm) were uniformly deposited within the mesoporous MMT support. This was attributed to the strong interaction between Ni and ceria and the confinement effect from the framework of MMT support. The catalytic activity and stability of Ni-Ce/MMT were studied in steam ethanol reforming and compared with Ni/MMT. The higher ethanol conversion and H-2 selectivity of Ni-Ce/MMT demonstrated the addition of ceria facilities the reaction of ethanol steam reforming. Additionally, the ethanol conversion was much more stable on Ni-Ce/MMT than on Ni/MMT during a long-term ethanol steam reforming reaction, illustrating that the catalyst deactivation was preferably suppressed with the help of ceria. In short, the Ni-Ce/MMT is a promising catalyst for ethanol steam reforming owing to the remarkable effect of ceria as well as the confinement effect of MMT support which can effectively suppress the Ni sintering and carbon deposition. (C) 2018 Elsevier Ltd. All rights reserved.