WO_3/ZrO_2固体强酸催化剂上异丁烷-丁烯烷基化反应研究(Ⅰ)──钨负载量和焙烧温度的影响

Studies on the Alkylation of Isobutane with Butene over WO_3/ZrO_2 Strong Solid Acid(Ⅰ)──Effect of Preparation, Load of WO 3 and Calcination Temperature

制备了系列 WO3/ Zr O2 固体强酸催化剂 ,用 XRD,DTA-TG,H2 -TPR,Raman光谱和酸性测定等方法测定其晶型结构、表面状态和酸性 .结果表明 ,WO3/ Zr O2 中的 Zr O2 基本以 T晶相存在 ,WO3对稳定 T晶相有重要作用 ,样品具有较大的表面积 .分散于 Zr O2 表面上的 WO3主要以单层分散和析出的 WO3晶粒形式存在 ,部分可能与 Zr O2 作用形成 Zr— O—W键并起强酸作用 .研究了各种实验条件下的异丁烷 -丁烯烷基化反应 .与其它固体酸相比 ,具有较高的起始活性和 i-C08选择性 。

A series of WO 3/ZrO 2 strong solid acid prepared under different conditions were studied. Their crystal structures, surface properties and acidities were determined by means of XRD, DTA TG, H 2 TPR, Laser Raman and acidity measurements. The results revealed that ZrO 2 in WO 3/ZrO 2 existed mainly in tetragonal phase, the addition of WO 3 plays an important role to stablize tetragonal phase of ZrO 2 and thus the catalyst had a considerable surface area. WO 3 in WO 3/ZrO 2 was dispersed and crystalized in WO 3 crystalite on ZrO 2 surface and partly reacted with ZrO 2 to form the bond of Zr—O—W, which acts as the strong solid acid site. The catalytic properties of WO 3/ZrO 2 strong solid acid for alkylation of iso butane with butene under the different conditions were investigated. They had a better reaction performance than other strong solid acids, a parallel relationship could be drawn between the catalytic activity and the amount of acid sites as well as the acidic strength of the catalysts.