Khaleel Abbas, Dellinger Barry
Department of Chemistry, Louisiana State University, Baton Rouge 70803, USA.
Environ Sci Technol. 2002 Apr 1;36(7):1620-4. doi: 10.1021/es010650i.
Chlorinated hydrocarbons are among the most recalcitrant pollutants for control by sorption or catalytic destruction. High surface-area alumina holds promise as a catalytic media as well as a component of other binary catalyst systems. We have prepared an alumina catalyst using the aerogel technique that has a very high surface area of 550 m2/g. This catalyst destroys carbon tetrachloride with an efficiency >99% at 400 degrees C. Its reactivity toward carbon tetrachloride is remarkably higher than that of commercial alumina, which has a surface area of 155 m2/g. Carbon dioxide is the major product. Minor products include hydrogen chloride and tetrachloroethylene along with traces of phosgene. Some of the carbon tetrachloride reacts with the alumina to form aluminum chloride, which vaporizes to reveal a fresh catalytic surface. A mechanism for adsorption and destruction has been developed that involves chemisorption followed by surface to adsorbate oxygen transfer and adsorbate to surface chlorine transfer.
氯代烃是最难通过吸附或催化分解来控制的污染物之一。高表面积氧化铝有望成为一种催化介质以及其他二元催化剂体系的一个组分。我们利用气凝胶技术制备了一种氧化铝催化剂，其具有550平方米/克的非常高的表面积。该催化剂在400摄氏度时对四氯化碳的分解效率>99%。它对四氯化碳的反应活性明显高于表面积为155平方米/克的市售氧化铝。二氧化碳是主要产物。次要产物包括氯化氢和四氯乙烯以及微量的光气。一些四氯化碳与氧化铝反应形成氯化铝，氯化铝蒸发后暴露出新鲜的催化表面。已经开发出一种吸附和分解的机制，该机制涉及化学吸附，随后是表面到吸附质的氧转移以及吸附质到表面的氯转移。
