New CoO-SiO2-Sol pillared clays as catalysts for NOx conversion
New CoO-SiO2-Sol pillared clays as catalysts for NOx conversion
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DOI：
10.1021/cm020201x
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发表时间：
2002-09-01
影响因子：
8.6
通讯作者：
Kim, HJ
中科院分区：
文献类型：
--
作者：
Choy, JH;Jung, H;Kim, HJ
以正硅酸乙酯（TEOS）为原料，在Co2+存在下，通过烷基铵插层蒙脱石，通过层间水解缩合反应合成了新型CoO-SiO2-溶胶柱撑蒙脱石（Co-SiM）。用十六烷基三甲基铵阳离子将钠基蒙脱石的硅酸盐层膨胀至约22埃，然后在正十二胺作为共模板剂的存在下与TEOS和CoCl_2·6 H（2）O的混合溶胶溶液反应。在550 ℃去除有机模板剂后得到微孔Co-SiM。柱撑样品的氮气吸附-脱附等温线表明，在硅酸盐层之间产生了大量的微孔，从而产生了高的BET比表面积（S-BET =约570 m（2）/g）和孔体积（V =约0.65 mL/g）。根据X-射线光电子能谱和X-射线吸收谱，发现掺入的钴物种是CoO，它均匀地分散在SiO2柱的表面上。Co-SiM具有优异的NO转化率，约为100%。在200 ℃时为50%，在500 ℃时持续增加至80%。
New CoO-SiO2-sol pillared montmorillonite (Co-SiM) is synthesized by interlamellar hydrolysis and condensation of tetraethyl orthosilicate (TEOS) in the presence of Co2+ ion via an alkylammonium intercalated montmorillonite. The silicate layers of Na+-montmorillonite are expanded in advance with hexadecyltrimethylammonium cation up to similar to22 Angstrom, followed by reaction with a mixed sol solution of TEOS and CoCl2.6H(2)O in the presence of n-dodecylamine as a cotemplate. A microporous Co-SiM is obtained after removing the organic templates at 550 degreesC. The nitrogen adsorption-desorption isotherm for the pillared sample reveals that a large number of micropores are created between the silicate layers, giving rise to a high BET specific surface area (S-BET = similar to570 m(2)/g) and a pore volume (V = similar to0.65 mL/g). According to the X-ray photoelectron and X-ray absorption spectroscopy, the incorporated cobalt species is found to be CoO, which is homogeneously dispersed on the surface of the SiO2 pillars. The Co-SiM exhibits an excellent NO conversion rate of ca. 50% at 200 degreesC, which continuously increases up to 80% at 500 degreesC.