Amination application over nano-Mg-Ni hydrogen storage alloy catalysts

Abstract

Some nano-intermetallic alloys such as Mg-Ni were prepared by a chemical reduction method (named polyol process) using ethylene glycol, polyvinyl pyrroli done (PVP 10000) and PdCl2 as reduction reagent, protect reagent, and nuclear reagent, respectively, to reduce the metal salts. The particle size of the synthetic Mg-Ni alloy was affected by the amount of the protect agent and nuclear agent and by the reduction temperature. All synthetic Mg-Ni alloys possess higher surface area about 113-315 m(2)/g and four kinds of components: Mg2Ni, Ni, Mg and MgO. The contents of Mg2Ni, Ni, Mg and MgO are affected by the Mg/Ni molar ratio. High molar ratio of Ni makes the single phase of Ni easy to reduce and results in the increase of Ni crystalline degree. The results of XRD and TEM and electron diffraction pattern indicate that PVP concentration only changes the particle size, but not the structure and composition of synthetic Mg-Ni alloys. The catalytic studies of PEG amination show that the total amine yield reaches to 58.4% over 1 g of Mg-Ni alloy with Mg:Ni = 1:2 due to the formation of more single phase of Ni. The formation of Mg2Ni alloy and MgO prevent the aggregation of Ni, and possesses a higher amination activity. (C) 2004 Published by Elsevier B.V.