Synthesis Of Pt/Co Bimetallic Nanoparticles Encapsulated Within UiO-66 And Their Catalytic Hydrogenation Application

Metal-organic frameworks(MOFs)are a new class of porous materials formed by the self-assembly of metal ions and organic linkers.They possess acceptable chemical stability,large specific surface area,porosity,tunable structure and properties.Hence,MOFs could be highly promising support materials for supporting or encapsulation of metal nanoparticles.Consequently,various methodologies have been developed to incorporate MNPs into MOFs,principally through a two-step or even multistep procedure.In this thesis,we developed a facile and efficient one-step strategy for the preparation of MOFs encapsulated surfactantsfree alloy metal nanoparticles,which exhibited extremely high catalytic performance for reduction of nitrobenzene.First,we have demonstrated a simple one-step strategy to form surfactants-free PtCo@UiO-66 composite materials.The materials were characterized by AAS,BET,TEM and XPS etc.The results showed that the highly dispersed and uniform Pt-Co NPs had been successfully encapsulated within the UiO-66 framework.The Pt and Co precursors were reduced by DMF and H2 as reducing agents,and the mean size of Pt-Co clusters were around2 nm.The prepared PtCo@UiO-66 materials were utilized as catalysts for the selectively hydrogenation of nitrobenzene.The as-synthesized PtCo@UiO-66 materials showed excellent activities and selectivities under atmospheric pressure of H2 and room temperature.When the Pt/Co molar ratio was 8:1,the PtCo@Ui O-66 showed the highest catalytic activity,which was mainly due to the suitable synergistic effect of the two metals.Moreover,the catalyst could be easily recovered and reused for 5 times without significant loss in activity and selectivity.This work represents the first example of incorporation of surfactant-free bimetallic NPs into the matrices of MOFs by employing a facile one-step strategy.