Synthesis of highly dispersed boron-promoted nickel nanocatalysts and significantly enhanced catalytic performance in hydrodechlorination of chlorobenzene

Abstract

Control of the dispersion and size of metallic nanoparticles, as well as metal–support interaction, is of vital importance to enhance the catalytic performance of supported metal nanocatalysts. In this work, carbon-supported boron-promoted Ni nanocatalysts (B–Ni) were synthesized via an in situ self-reduction process of hybrid borate-intercalated NiAl-layered double hydroxide/carbon nanocomposites, and the promotional effect of boron on the catalytic performance of Ni nanocatalysts formed in liquid phase hydrodechlorination of chlorobenzene was studied. A series of XRD, TEM, STEM, XPS, low temperature N₂ adsorption, and H₂ chemisorption results revealed that the resulting spherical B-modified Ni nanoparticles were homogeneously dispersed and anchored tightly on the surface of the carbon support. A suitable amount of boron was essential for the formation of highly dispersed and uniform nanoparticles and pronounced surface Ni–B interaction, as well as strong Ni–B–support interactions, accounting for the significantly enhanced hydrodechlorination activity, in comparison with a B-free Ni catalyst. Moreover, as-synthesized B–Ni nanocatalysts exhibited good stability, without obvious aggregation and loss of active species after five recycles.