Ni2P promotion for the high hydrogenation activity of naphthalene on wrinkle silica nanoparticles with tunable hierarchical pores sizes in a large range

A series of the wrinkle silica nanoparticles with hierarchical pores (HPWSNs) supports were successfully prepared by dual-templating, of which the special wrinkle pore structure in the monodisperse HPWSNs samples were beneficial to reduce the diffusion resistance of macromolecular aromatic compounds and contributed to the high dispersion of Ni2P active phases. And the distance between wrinkles in silica nanoparticles could be easily tuned by changing the ratios of SDS/CTAB through the charge-reversed interactions. It was found that Ni2P/HPWSNs-0.13 catalyst with the smallest Ni2P particles had the highest surface areas and the biggest pore volume. Furthermore, the Ni2P/HPWSNs-0.13 catalyst exhibited the highest naphthalene hydrogenation conversion as well as 99.9 % selectivity of decalin at 320 oC. To trace the microscale reason, DFT calculation was performed and the results showed that the stronger adsorptions of naphthalene and tetralin over Ni(2) sites were observed than those over Ni(1) sites. Therefore, it can be concluded that the superior catalytic activity of Ni2P/HPWSNs-0.13 catalyst could be ascribed to the synergistic effect of the center-radical framework structure and the small sizes of Ni2P particles, which are conducive to exposing more Ni(2) sites on the support surface, thus inducing more H for naphthalene hydrogenation reaction.