ORMOSIL-entrapped copper complex as electrocatalyst for the heterogeneous de-chlorination of alkyl halides

The development of an efficient method for the de-halogenation of alkyl halides is an essential step towards the elimination of these pollutants from the environment. Here we show that entrapment of an electro-catalyst in sol-gel electrodes yields efficient electrodes for this process. In this study Cu(1,4,8,11-tetra-aza-cyclo-tetra-decane)2+ was used as the active catalyst in the de-chlorination of CCl3CO2-. The major electro-catalytic product is oxalate while a minor product, depending on experimental conditions, is either glyoxalate or acetate. The efficiency of the electro-catalytic process depends on the nature of the precursors used to prepare the sol-gel matrix. The observed electro-catalytic current decreases when cyclic voltammetry is performed at high scan rates. This surprising result indicates that the mechanism of the electro-catalytic process is dependent on the scan rate. Plausible mechanisms at low and high scan rates are proposed.

开发一种高效脱卤代烷基卤化物的方法，对于从环境中消除此类污染物至关重要。本研究中，我们展示了将电催化剂封装于溶胶-凝胶电极中可制备出用于该过程的效率较高的电极。在此次研究中，Cu(1,4,8,11-四氮杂环四癸烷)2+被用作CCl3CO2-脱氯反应的活性催化剂。主要的电催化产物为草酸盐，而根据实验条件，次要产物可能为乙二醛或乙酸。电催化过程的效率取决于制备溶胶-凝胶基质的先驱物质的性质。在高扫描速率下进行循环伏安法时，观察到的电催化电流降低。这一令人惊讶的结果表明，电催化过程的机理依赖于扫描速率。针对低扫描速率和高扫描速率下的可能机理提出了合理的假设。