Selective chemisorption of carbon monoxide by organic-inorganic hybrid materials incorporating cobalt(III) corroles as sensing components
Selective chemisorption of carbon monoxide by organic-inorganic hybrid materials incorporating cobalt(III) corroles as sensing components
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DOI：
10.1002/chem.200601143
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发表时间：
2007-01-01
影响因子：
4.3
通讯作者：
Guilard, Roger
中科院分区：
文献类型：
--
作者：
Barbe, Jean-Michel;Canard, Gabriel;Guilard, Roger
采用溶胶-凝胶法或将钴（III）配合物接枝到SBA-15型介结构二氧化硅上，合成了21种含钴（III）配合物的杂化材料。在以化学吸附现象为主的低压区，所有材料对一氧化碳都表现出几乎无限的选择性。这种特殊的性质对于CO传感器的应用是至关重要的。在主要发生非选择性物理吸附现象的高压下，选择性略有降低。CO化学吸附活性位点的比例在22% ~ 64%之间。这个低百分比可能是由于钴（III）与材料表面残留的硅醇或硅氧烷基团之间的相互作用，阻止了CO分子的进一步配位。值得注意的是，最有效的材料是在凝胶化或接枝过程中有保护配体（吡啶）存在的材料。胶凝过程后，这种配体的Ne去除会在钴离子周围释放一个有利于一氧化碳分子配位的空腔。在几个月的时间里，SBA-15杂化材料的CO吸附性能没有受到影响，这表明材料具有很高的稳定性。相反，由于材料结构的演变，干凝胶容量缓慢下降。
Twenty-one hybrid materials incorporating cobalt(III) corrole complexes were synthesized by a sol-gel process or by grafting the metallocorrole onto a mesostructured silica of the SBA-15 type. All the materials show an almost infinite selectivity for carbon monoxide with respect to dinitrogen and dioxygen in the low-pressure domain where the chemisorption phenomenon is predominant. This peculiar property is of prime importance for an application as a CO sensor. The selectivity slightly decreases at high pressures where nonselective physisorption phenomena mainly occur. The percentage of active sites for CO chemisorption ranges from 22 to 64%. This low percentage may be attributable to interactions between the cobalt(III) corroles with silanol or siloxane groups remaining at the surface of the materials which prevent further coordination of the CO molecule. Notably, the most efficient materials are those prepared in the presence of a protecting ligand (pyridine) during the gelation or the grafting process. ne removal of this ligand after the gelation process releases a cavity around the cobalt ion that favors the coordination of a carbon monoxide molecule. The CO adsorption properties of the SBA-15 hybrid were not affected over a period of several months thus indicating a high stability of the material. Conversely, the xerogel capacities slowly decrease owing to the evolution of the material structure.