Host-guest chemistry immobilized nickel nanoparticles on zeolites as efficient catalysts for amination of 1-octanol

Nickel silicate and NiAl-LDHs (layered double-hydroxides) have been controllably fabricated on the crystal surface of Si-rich and Al-rich USY zeolites, respectively, through a distinctive in-situ hydrothermal growth approach. This was realized by the host-guest chemistry that induced chemoselective interactions between adscititious Ni source and constituent species of zeolite framework. Upon hydrogen reduction, nickel silicate and NiAl-LDHs were transformed to highly dispersed Ni nanoparticles (NPs) immobilized in the SiO₂ and Al₂O₃ matrix, respectively, which were firmly anchored around the USY crystals. The controllable immobilization of Ni NPs created well preserved hierarchical porosity in USY zeolites. With highly dispersed metallic Ni active sites in Al₂O₃ matrix supported on USY zeolite, the USY@Ni-3 catalyst exhibited similar conversion but significantly enhanced selectivity in the reductive amination of 1-octanol to corresponding alkylamines in comparison to conventional Raney Ni catalyst.