Intercalated structured nickel-based hydrotalcite nanocatalyst for diphenylacetylene semihydrogenation

Abstract

<p indent=0mm>A novel nickel-based hydrotalcite catalyst Ni/Mg₃Al₁O-PDA was fabricated by intercalating the complex formed by pyridine-2,3-dicarboxylic acid (PDA) and nickel ions into the layers of Mg-Al hydrotalcite. Compared with nickel-based nanocatalysts prepared by traditional impregnation method and co-precipitation method, this catalyst showed superior catalytic performance in the semi-hydrogenation of 1,2-diphenylacetylene. Results of X-ray powder diffraction, infrared spectrum, transmission electron microscopy and X-ray photoelectron spectroscopy showed that the intercalation effect of Ni-PDA effectively promoted the uniform dispersion of Ni precursors between hydrotalcite laminates, and increased the intercalation distance of hydrotalcite laminates from 0.76 to <sc>1.55 nm.</sc> This process not only facilitated the high dispersion of Ni nanoparticles, but also increased the specific surface area and pore volume of the catalyst, thus exposing more Ni active sites. Moreover, the formation of MgNiO₂ spinel structure in the catalyst precursors significantly improved the interaction between the active species and the support, promoted the dispersion of Ni nanoparticles, and improved the activity and stability of the obtained catalyst.