Bettahar M M, Wojcieszak R, Monteverdi S
UMR 7565, Catalyse Hétérogène, Faculté de Sciences, Université Henri Poincaré, Nancy-I, BP 239, 54506 Vandoeuvre-lès-Nancy Cedex, France.
J Colloid Interface Sci. 2009 Apr 15;332(2):416-24. doi: 10.1016/j.jcis.2008.12.068. Epub 2009 Jan 30.
A series of bimetallic NiAg (Ni + Ag = 1% wt) catalysts supported on amorphous silica was synthesized via chemical reduction using hydrazine as the reducing agent at 353 K. Catalysts were prepared via impregnation or precipitation technique. It was found that the reduction of the Ni(2+) ions occurred only in the presence of silver, otherwise a stable blue Ni(N(2)H(4))(3) complex was formed. Comparisons with similar NiAg catalysts supported on crystallized silica as prepared in our previous work indicated that the Ni(2+) ions weakly interacted with acidic crystallized silica on which they were readily reduced. For both supports, the combination of silver and nickel gave rise to a synergistic effect due to the existence of NiAg groupings. The surface and catalytic properties of the metal particles formed depended on the Ni:Ag ratio, method of preparation, and acidity of the support.
通过在353K下使用肼作为还原剂进行化学还原，合成了一系列负载在无定形二氧化硅上的双金属NiAg（Ni + Ag = 1%重量）催化剂。催化剂通过浸渍或沉淀技术制备。发现Ni(2+)离子仅在银存在的情况下发生还原，否则会形成稳定的蓝色Ni(N₂H₄)₃络合物。与我们之前工作中制备的负载在结晶二氧化硅上的类似NiAg催化剂进行比较表明，Ni(2+)离子与酸性结晶二氧化硅弱相互作用，在其上它们很容易被还原。对于两种载体，由于存在NiAg基团，银和镍的组合产生了协同效应。形成的金属颗粒的表面和催化性能取决于Ni:Ag比、制备方法和载体的酸度。
