| Supported metal catalysts was synthesized with TiO2 and TiO2/cordierite as carrier and supporting metal salt by the method of hydrothermal synthesis, then baking at 500℃and soaking in kalium borohydride(KBH4) solution. For the catalyst of Fe-Ni-B/TiO2 that using TiO2 as carrier, it's performance of preventing oxidation after reduction in H2 atmosphere has been improved by supporting Ag on the surface of it. In-depth research has been done on the preparation technics for the catalyst of Fe-Ni-B/TiO2/cordierite. Research shows that the best preparation technics and conditions for the catalyst is hydrothermal synthesis at 150℃→baking at 500℃for 3 h→soaking in KBH4→reduction in H2 atmosphere at 400℃. Using this preparation technics and conditions, simplex component supported metal catalysts was prepared by taking FeSO4·7H2O, Fe(NO3)3·9H2O, FeCl2-4H2O, Co(NO3)2·6H2O, CoSO4·7H2O, CoCl2·6H2O, Ni(NO3)2·6H2O, NiSO4·6H2O and NiCl2·6H2O as dipping solution respectively. Study shows that the longevity of service of catalyst was abridged after reduction in H2 atmosphere, and simplex component supported metal catalysts was prepared without reduction in H2 atmosphere. Catalytic property for hydrogen evolution shows that the catalysts of Fe/TiO2/cordierite and CoTiO3/cordierite which take Fe(NO3)3·9H2O and CoCl2·6H2O as dipping solution respectively has the best catalytic property for hydrogen evolution.Catalytic property for hydrogen evolution has been improved obviously by soaking the catalyst in KBH4. For the catalyst of Fe/TiO2/cordierite, in the course of the catalyst soaking in KBH4, the ferric oxide was deoxidized as elementoid iron, and XRD and XPS all show that the component of elementoid iron has the Catalytic property for hydrogen evolution. For the catalyst of CoTiO3/cordierite, powder blue on the surface of the catalyst cumber the catalytic property for hydrogen evolution, but the KBH4 can deoxidize the powder blue as elementoid cobalt and the elementoid cobalt can fall off from the surface of the catalyst, XRD and XPS all show that soaking the catalyst in KBH4 can achieve the aim of using the activity component of CoTiO3 catalyze hydrogen evolution adequately.The content of Co on the surface of the catalyst of CoTiO3/cordierite was determined by ultraviolet-spectrometer, the result of research shows that as the increasing of the content of Co on the surface of the catalyst, the catalyst has higher performance of catalyze hydrogen evolution. Experiment shows that when taking saturated CoCl2·6H2O as dipping solution, the catalyst can achieve the best catalytic property for hydrogen evolution on the whole, when taking supersaturation CoCl2·6H2O as dipping solution, the supporting capacity manifold, but the activity component will fall off when catalyze hydrogen evolution.The catalyst of CoTiO3/cordierite has excellent performance of catalytic hydrolysis in alkaline, especially when the kalium borohydride solution with approximate 18% NaOH, it has the best performance of catalyze hydrogen evolution. The reason for that maybe because as the concentration increasing, the tangent state between the solution of KBH4 and the surface of the catalyst changed, so the flowing impact of the solution of KBH4 on the surface of the catalyst has been improved.SEM shows that the surface of the catalyst is sheet CoTiO3 that thickness is many decades nanometer, ratio surface area and aperture distributing test show that the ratio surface area of the catalyst is 5.58 m2·g-1, average aperture distributing is 14.91 nm. |
PDF Full Text Request