Studies On The Properties And Modification Of Amorphous NiB Alloy Catalysts

Amorphous NiB and NiBSm alloys have been prepared by chemical reduction method and the fixed alloys prepared by chemical reduction method combined with mechanically mixing or with impregnation for the first time. The hydrogenation of styrene, benzene, ethyne and carbon dioxide are selected as probe reaction. The techniques of pulse and continuousmicroreaction are applied to study the effect of the concentration of the reductant KBH₄, pretreatment in N₂, fifteen rare earth elements and four supports on the catalyticactivities and stabilities of NiB alloy for series hydrogenation. The sulfur resistance character is determined by pulse CS₂ poisoning method. The bulk structure and composition of the alloys are examined by XRD and ICP, respectively. The thermal stablity of the samples is studied by DSC. The morphology of the alloy particles is observed by TEM and the disperse of them are determined by CO chemical absorption method. TPR. TPD. TPSR. XPS and so on have been used to charaterize the surface properties of the alloys such as reduction, absorbing, the types and character of the active sites over the surface of the samples, surface composition and electron state. TG is used to research the reason for rapidlydeactivation for ethyne hydrogenation over the alloys catalysts and to study the effect of rare earth and support on the number of carbon deposition as well. Sepoite, as a new kind of support, has been modified by acid. The effects of acid modification on the specific surface area and the distribution of the pore radius of sepoite are examined by N₂ absorption methos. Dynamic studies on the pulse reaction for benzene...