The Study Of Preparation And Properties Of Nano-catalyst

Cu-Pd cubic nanocrystals （NCs） with controlled compositions weresynthesized by the reduction of Copper chloride dehydrate and Sodiumtetrachloropalladate in the presence of oleylamine （OAm） during thedehydrogenation of ammonia-borane （AB） in THF under vacuum at roomtemperature. It is the one of only a few heterogeneous nanoalloy catalysts in NCsnot only greatly reduces the noble-metal usage but also could significantly enhancetheir catalytic properties during the dehydrogenation of AB. X-ray diffractometer（XRD） and transmission electron microscopy （TEM） are employed to characterizeand analyze the synthesized Cu-Pd NCs. Among the different ratios of Cu to PdNPs, Cu_0.5Pd_0.5catalysts exhibited the highest catalytic activity, and clearlyindicating the formation of a metallic alloy. The synergy between Cu and Pd in Cu-Pd NCs for dehydrogenation of ammonia borane is very obvious. What`s more, thework reported here includes a wealthy collection of kinetic data to determine therate law and apparent activation energy for the catalytic dehydrogenation of AB.We have prepared a low-cost, facile, but very efficient method to overcomethe deactivation of Co NPs. Through an oxidative etching process, the Co NPs canbe easily converted into Co²⁺in the reaction solution in air. But the Co²⁺is verylong-time stable for easy storing in aqueous solution, and it can be rapidly reducedback to Co NPs for recycle application. In air, the regenerated Co NPs remain theirinitial high activity for ab hydrolysis. For future development on the practical on-board hydrogen-storage and supply materials, such metal-metal ion conversionprocess may represent a new strategy to overcome the oxidative deactivation ofnon-noble catalysts.