Effects of Promoters on the Structure, Performance, and Carbon Deposition of Ni-Al(2)O(3) Catalysts for CO(2)–CH(4) Reforming

[Image: see text] Modified Ni-Al(2)O(3) catalysts with Ca, Co, and Ce species as promoters were prepared by the combustion method, and the structure, morphology, reduction characteristic, and CO(2)–CH(4) reforming of the catalysts were discussed by X-ray diffraction (XRD), H(2)-temperature-programmed reduction (H(2)-TPR), energy-dispersive X-ray (EDX) mapping, NH(3)-temperature-programmed desorption (NH(3)-TPD), N(2) adsorption–desorption, thermogravimetric-differential thermal analysis (TG-DTG), and temperature-programmed hydrogenation (TPH) methods. The crystal size of Ni on Ca-Ni-Al(2)O(3) was 16.97 nm, and the active component and additive were distributed well in the catalyst. Co-Ni-Al(2)O(3) presented a surface area of 65.70 m(2)·g(–1) and a pore diameter of 161.60 nm. Ce-Ni-Al(2)O(3) showed relatively stable nickel–aluminum spinel (NiAl(2)O(4)), which could not be easily reduced to the active component Ni. Evaluation results demonstrated that the performance of the catalysts followed the order Co-Ni-Al(2)O(3) > Ca-Ni-Al(2)O(3) > Ni-Al(2)O(3) > Ce-Ni-Al(2)O(3). Carbon deposition analysis showed that the carbon resistance of Ca-Ni-Al(2)O(3) was poor and graphitic carbon was generated on the catalyst. However, Ce-Ni-Al(2)O(3) showed less carbon deposition, which might have resulted from the lower activity of the catalyst.