期刊
CATALYSIS TODAY
卷 174, 期 1, 页码 25-30出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.cattod.2011.03.070
关键词
Hydrogen sulfide oxidation; Sulfur selectivity and yield; Rare earth orthovanadates; Antimony oxide; Site isolation; Electronegativity
Three R-E-V-Sb (R-E was Sm, Y, and La) mixed-oxide catalysts were prepared for catalyzing the selective oxidation of hydrogen sulfide to sulfur. The multiphase R-E-V-Sb catalysts were characterized by TPR, XRD, SEM and BET techniques. Synergistic phenomena in sulfur yield were observed with the solid-state reaction between REVO4 and alpha-Sb2O4 (antimony oxide/REVO4 weight ratio = 1/3), which was ascribed to the formation of SbVO4 species. Under identical reaction conditions, areal reaction rate decreased in the following order: Sm-V-Sb > La-V-Sb similar to LaVO4 > Y-V-Sb > SmVO4 > YVO4. All R-E-V-Sb catalysts exhibited 100% sulfur yield in a certain temperature range. The temperature window width for 100% sulfur yield decreased in the following order: La > Sm > Y, which was the same as the order of decreasing ionic radius (La > Sm > Y) and the order of increasing RE electronegativity (La < Sm < Y). The selectivity difference was explained in terms of active site isolation and product desorption effects. The rare earth cation size effect observed here for H2S oxidation to elemental sulfur was similar to the alkali cation size effect reported for the hydrocarbon oxidation. (C) 2011 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据