锌/银二元金属体系中五氯吡啶的电催化还原脱氯

Electrical catalytic dechlorination of pentachloropyridine in Zn/Ag bimetallic system

研究了Zn/Ag二元金属体系对五氯吡啶的催化还原脱氯性能。实验考察了初始pH值、催化剂的投加量、反应温度等参数对反应的影响,在此基础上探讨了其脱氯机理。实验结果表明:反应温度为60℃时,单一锌粉能够对五氯吡啶进行还原脱氯生成四氯吡啶,但是收率不高,只有20%左右,在银的催化作用下,四氯吡啶收率得到了很大提高。当反应初始pH控制在弱酸条件下(5左右),硝酸银浓度为10 g·L^(-1)时,反应3h后四氯吡啶收率可达到60%以上。在Zn/Ag双金属表面,五氯吡啶的脱氯反应符合一级反应,速率常数为0.0097 min^(1)。

Dechlorination of pentachloropyridine catalyzed by Zn/Ag bimetal particles was studied in this work.The effects of initial pH of the system,amount of catalyst and reaction temperature on the reaction were studied.The results showed that the zinc powder could be used to reductively dechlorinate pentachloropyridine to tetrachloropyridine with its yield about 20%.Under the catalytic effect of silver,the dechlorination efficiency of pentachloropyridine was greatly improved.When the initial pH was about 5, the concentration of silver nitrate was 10 g·L^(-1),the yield of tetrachloropyridine could be above 60%.The reaction took place on the bimetal surface in a first order reaction,and the rate constant was 0.0097 min^(-1).