Dechlorination of chloroacetic acids by Pd/Fe nanoparticles: Effect of drying method on metallic activity and the parameter optimization
Dechlorination of chloroacetic acids by Pd/Fe nanoparticles: Effect of drying method on metallic activity and the parameter optimization
复制标题
Pd/Fe纳米颗粒对氯乙酸脱氯：干燥方法对金属活性的影响及参数优化
DOI：
10.1016/j.apcatb.2009.10.020
复制
发表时间：
2010-02-01
影响因子：
22.1
通讯作者：
Ma, Jun
中科院分区：
文献类型：
--
作者：
Wang, Xiangyu;Ning, Ping;Ma, Jun
将实验室合成的湿式Pd/Fe纳米粒子分别用直接烘箱干燥法和溶剂替代烘箱干燥法进行干燥，得到两种干燥的Pd/Fe纳米粒子（Pd/Fe-1和Pd/Fe-2）。比较了两种干燥方法，考察了干燥过程中使用的洗涤试剂对Pd/Fe纳米粒子催化氯乙酸脱氯的理化性质和活性的影响。用六氯代酸钾溶液浸渍铁纳米粒子制备Pd/Fe纳米粒子，用不同的试剂（去离子水和有机溶剂）洗涤，然后在100℃的烘箱中真空干燥，用比表面积（BET-N-2）、形貌（SEM）、表面元素分布（EDS）和粒径（TEM）对制备的Pd/Fe-1和Pd/Fe-2纳米粒子进行表征。通过三氯乙酸（TCAA）、二氯乙酸（DCAA）和一氯乙酸（MCAA）的脱氯反应，考察了Pd/Fe-1和Pd/Fe-2纳米颗粒的催化活性。Pd/Fe-2对氯乙酸的去除率比Pd/Fe-1高58.5 ~ 22.7%。确定了提高氯乙酸去除率的最佳Pd含量、金属负荷量和反应体系初始pH值。考察了pH值的变化、氯乙酸的脱氯途径和动力学。氯乙酸的去除率依次为TCAA > DCAA > MCAA，反应速率常数k（obs）分别为1.113 × 10（-1）、1.278 × 10（-2）和1.900 × 10(-3) min（-1）。(C) 2009 Elsevier B.V.版权所有
Two kinds of dry Pd/Fe nanoparticles (Pd/Fe-1 and Pd/Fe-2) were obtained by drying the laboratory synthesized wet Pd/Fe nanoparticles with direct oven drying method and solvent replacement oven drying method, respectively. A comparison was made between the two drying methods, concerning the effects of the washing reagents used during the drying process on the physicochemical properties and the activities of Pd/Fe nanoparticles for catalytic dechlorination of chloroacetic acids. Pd/Fe nanoparticles prepared by impregnation of iron nanoparticles with an aqueous solution of potassium hexachloropalladate were washed with different reagents (deionized water and organic solvents), followed by vacuum drying in an oven at 100 degrees C. The prepared dry Pd/Fe-1 and Pd/Fe-2 nanoparticles were characterized in terms of specific surface area (BET-N-2) morphology (SEM), surface elemental distribution (EDS), and particle size (TEM). The catalytic activities of Pd/Fe-1 and Pd/Fe-2 nanoparticles were evaluated via dechlorination reaction of chloroacetic acids including trichloroacetic acid (TCAA), dichloroacetic acid (DCAA), and monochloroacetic acid (MCAA). The removal efficiencies of chloroacetic acids by Pd/Fe-2 were about 58.5-22.7% greater than that achieved by Pd/Fe-1. The optimal Pd content, the amount of metal loading, and the initial pH value of reaction system for higher removal efficiency of chloroacetic acids were determined. The variation of pH value, dechlorination pathway and kinetics of chloroacetic acids were also investigated. The removal efficiencies of chloroacetic acids followed the order of TCAA > DCAA > MCAA with observed reaction rate constant (k(obs)) values of 1.113 x 10(-1), 1.278 x 10(-2), and 1.900 x 10(-3) min(-1), respectively. (C) 2009 Elsevier B.V. All rights reserved.