Amine functional silica-supported bimetallic Cu-Ni nanocatalyst and investigation of some typical reductions of aromatic nitro-substituents

Herein, preparation and application of amine functionalized silica (NH2-SiO2)-supported Cu-Ni nanocatalyst are reported. Cu-Ni nanoparticles (NPs) are doped on the NH2-SiO2 support via in situ simultaneous reduction of Cu and Ni ions. The X-ray diffraction (XRD) pattern revealed the face-centered-cubic (fcc) crystalline alloy structure of Cu-Ni NPs in the NH2-SiO2/Cu-Ni nanocatalyst. X-ray photoelectron spectroscopy (XPS) analyses showed that anchored Cu-Ni NPs contained Cu-0 and Cu2+ species, while Ni was present at its bivalent state (Ni2+). In comparison to the unsupported Cu-Ni bimetal NPs, the supported NH2-SiO2/Cu-Ni nanocatalyst showed superior catalytic activity in chemical reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), giving 98.5% conversion at pH 6 within 15 min. The kinetics preferably followed the pseudo-first-order rate model. The NH2-SiO2/Cu-Ni nanocatalyst is recoverable magnetically from the reaction media and can be recycled up to six cycles without much loss in catalytic activity.

Automated summary

Preparation and application of amine functionalized silica (NH2-SiO2)-supported Cu-Ni nanocatalyst is reported, demonstrating superior catalytic activity in the chemical reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with high conversion rate and good recyclability.