Facile Synthesis and Catalytic Properties of Nickel-Based Mixed-Metal Oxides with Mesopore Networks from a Novel Hybrid Composite Precursor

Facile synthesis of high-surface-area nickel-based mixed-metal oxides with interconnected mesopore networks through a novel layered double hydroxide/carbon (LDH/C) hybrid composite precursor route is successfully established. The starting LDH/C composite with interwoven framework structure is assembled by the crystallization of Ni/Al layered double hydroxide simultaneously accompanied by the carbonization of glucose under mild hydrothermal conditions, and subsequently, the formed composite is thermally decomposed to generate mesoporous nickel-based mixed-metal oxides after removal of the carbon. The materials have been characterized by X-ray diffraction (XRD), Fourier transform infrared technique (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen sorption measurements. The results elucidate that the specific surface area of calcined LDH/C composite at 450 °C can be as high as 288 m 2 g −1, and decreases gradually with the calcination temperature. The effect of in situ generated carbon as template in the composite precursor is an essential factor to direct the formation of the high-surface-area mixed oxides with interconnected mesopore network. And the porosity of the obtained solids can be dominated by adjusting the calcination temperature of precursors. Furthermore, through catalytic investigations, these as-prepared high-surface-area Ni-based mixed oxides display excellent catalytic activities for the growth of carbon nanotubes in chemical vapor deposition reactions.