三维Pd/OMC粒子电极体系电催化泛影酸盐还原脱碘研究

以泛影酸盐(DTZ)的高效还原脱碘为目标,通过硼氢化钠还原法制备钯负载有序介孔碳(Pd/OMC)作为粒子电极,以碳纤维(CFP)电极作为主阴极,建立了三维电极电催化还原体系.该体系在低阴极电位下(-0.6～-0.8 V)可实现电化学/感应电化学的耦合还原,其脱碘速率是单独阴极体系的2.38～3.65倍;在阴极电位高于析氢电位(-1.5 V)时,可实现电化学/感应电化学/化学催化加氢多还原过程协同去除碘代有机物,其反应速率为单独阴极体系的1.27～4.69倍.进一步研究了DTZ初始浓度、Pd/OMC投加量及Pd的负载量对DTZ还原去除的影响.电化学测试结果表明三维电化学体系具有良好的电子传递能力与电还原性能.利用自由基淬灭实验与ESR自由基捕获对活性还原物种分析,表明原子H~*在三维电化学还原脱碘过程中起重要作用.

Reductive deiodination of diatrizoate by three-dimensional electrochemical system based on Pd/OMC particle electrodes

A three-dimensional electrocatalytic reduction system was established for the efficient reductive deiodination of DTZ, with the palladium-loaded ordered mesoporous carbon (Pd/OMC) prepared by the NaBH₄ reduction method as the particle electrodes and the carbon fiber paper (CFP) electrode as the cathode. This system can couple the cathodic reduction and inductive electrochemical reduction at low cathode potentials (from -0.6 to -0.8 V), with the deiodination rate 2.38~3.65 times higher than the individual CFP cathode system. When the cathode potential is negative than that of the hydrogen evolution reaction (-1.5 V), the multi reduction processes including cathodic reduction, inductive electrochemical reduction, and catalytic hydrogenation reduction can be combined in the electrochemical system, and the deiodination rate is 1.27~4.69 times higher than the individual CFP cathode system. The effects of initial DTZ concentration, Pd/OMC dosage, and Pd loading on DTZ removal were further investigated. Electrochemical analysis shows that the three-dimensional electrochemical system has high electron transfer rate and electrocatalytic reduction performance. The radical quenching experiment and ESR trapping results indicate that the atomic H^* plays an important role for the reductive deiodination in the three-dimensional electrochemical system.