Preparation and evaluation of the Ni-Al catalyst derived from LDHs synthesized on γ-Al_2O_3 support

摘要

In this paper, Ni-Al catalyst derived from LDHs was prepared. CH_4-CO_2 reforming was chosen as the probe reaction to evaluate the catalytic activity. The traditional catalyst with alike composition (Ni-Al-IMP) was also prepared as the reference. At the temperature range of 650-850, the Ni-Al-LDH catalyst exhibited a higher activity, and the side reaction of reverse water-gas reaction was inhibited. The related samples, including catalyst support, catalyst precursor, and catalyst, were characterized by XRD, SEM, and FT-IR. The results showed that the Ni-Al-LDH with CO_3~(2-) serving as the interlayer anion was successfully synthesized on the γ-Al_2O_3 support and presented in the layer structure. Ni existed as the divalent cation in this LDH and was present in the atomic-level dispersion, resulting in a smaller crystal size, better dispersion, and more active sites. It can be concluded that the highly dispersed Ni crystal played a key role in the enhanced catalytic activity of Ni-Al-LDH catalyst.