杨鑫宇,吴杰,解帅,吴纯鑫,张建庭,赵德明.纳米级Pd/Fe@SiO2复合颗粒对2,4-DCP的还原脱氯研究[J].环境科学学报,2019,39(11):3794-3801
纳米级Pd/Fe@SiO2复合颗粒对2,4-DCP的还原脱氯研究
- Reductive dechlorination of 2,4-DCP by Pd/Fe@SiO2 nanocomposites
- 基金项目：浙江省自然科学基金（No.LY19B070006）
- 杨鑫宇
- 浙江工业大学化学工程学院, 杭州 310014
- 吴杰
- 浙江工业大学化学工程学院, 杭州 310014
- 解帅
- 浙江工业大学化学工程学院, 杭州 310014
- 吴纯鑫
- 浙江工业大学化学工程学院, 杭州 310014
- 张建庭
- 浙江工业大学化学工程学院, 杭州 310014
- 赵德明
- 浙江工业大学化学工程学院, 杭州 310014
- 摘要：为有效抑制纳米级Pd/Fe颗粒的团聚和钝化及改善其表面特性，将纳米SiO2包覆在Pd/Fe颗粒表面，超声波辐照下液相还原法制备纳米级Pd/Fe@SiO2复合颗粒，采用TEM、SEM、XRD、EDX及BET表征其物性，以2，4-二氯苯酚（2，4-DCP）为目标污染物，探究其对2，4-DCP的还原脱氯影响因素、降解机理和动力学，结果表明：制备的纳米级颗粒粒径均匀、分散性好，比表面积大；体系中纳米级Pd/Fe投加量、钯化率、TEOS投加量、反应温度及溶液初始pH均会对2，4-DCP的降解效果产生明显影响；并推测出纳米级Pd/Fe@SiO2复合颗粒对2，4-DCP的降解机理即快速吸附-逐步脱氯-最终脱附释放，其降解符合拟一级动力学关系.
- Abstract：To inhibit the agglomeration and passivation of Pd/Fe nanoparticles and improve its surface properties, nano-SiO2 coated Pd/Fe particles (Pd/Fe@SiO2 nanocomposites) were prepared via a facile liquid phase reductive method with the aid of ultrasound irradiation, and were characterized by TEM, SEM, XRD, EDX, and BET. Thereafter, the catalytic performance of Pd/Fe@SiO2 was checked using the model reaction of 2,4-dichlorophenol (2,4-DCP) dechlorination, wherein the influential factors, degradation kinetics, and reaction mechanism were investigated. It can be found that:1) the highly dispersed, with uniform size and large surface area of Pd/Fe@SiO2 catalyst could be accounted for the superior activity of 2,4-DCP dechlorination; 2) several factors such as Pd/Fe nanoparticles dosage, palladium content, TEOS dosage, reaction temperature and initial pH significantly affect the degradation of 2,4-DCP; 3) the degradation of 2,4-DCP by Pd/Fe@SiO2 nanocomposites is rapid adsorption-gradual dechlorination-final desorption. following pseudo-first-order kinetics.
