| dc.description.abstract | Ni-B amorphous catalysts proved to be a better catalyst on both activity and selectivity for hydrogenation of p-chloronitrobenzene (p-CNB) from previous studies. However, the catalytic activity of Ni-B catalyst did not compete with that of noble metals viz., Pd and Pt. In order to enhance the catalytic activity of Ni-B for the hydrogenation, six additives were introduced into Ni-B amorphous catalyst, including metal salts of Cr, Ce, Th, W, Ru and Mo. A series of modified Ni-B amorphous nanocatalysts were prepared by chemical reduction of mixed salts of the metal additive and nickel acetate tetrahydrate with sodium borohydride in water/methanol solution. The characterization results revealed that at a specific weight ratio of metal dopants, some particles of modified Ni-B catalysts became smaller and have better thermal resistance, and protecting the special amorphous structure even at high temperature. During hydrogenation of p-CNB, some modified Ni-B catalysts have showed lower catalytic activity than unmodified one. However, the catalytic activity of these promoted catalysts are better than Raney nickel used in industries, with high selectivity to the main product of p-CAN (p-chloroaniline). Among these promoted catalysts, Mo-Ni-B showed the best activity and reached almost 100% conversions even at lower reaction temperature of 323K. According to kinetic studies and results of various characterization methods, such as powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and N2 sorption, the correlation of the catalytic performance to both the structural and the electronic characteristics have been arrived and discussed briefly. | en_US |