Pd/CeO_(2)对2,4-二氯苯氧乙酸的液相催化加氢脱氯  

Catalytic hydrodechlorination of 2,4-dichlorophenoxyacetic acid in liquid phase using Pd/CeO_(2)catalyst

作　　者：牛夕阳 余诗慧 杨娇娇 周娟[1] NIU Xiyang;YU Shihui;YANG Jiaojiao;ZHOU Juan(College of Environmental Science and Engineering,Donghua University,Shanghai 201620)

机构地区：[1]东华大学环境科学与工程学院,上海201620

出　　处：《东华大学学报（自然科学版）》2023年第2期136-143,149,共9页Journal of Donghua University(Natural Science)

基　　金：上海市自然科学基金资助项目(19S11307)。

摘　　要：采用NaBH4还原法分别制备了不同载体CeO_(2)、活性炭(AC)和石英砂(SiO_(2))的负载型Pd基催化剂。采用Zeta电位、X射线衍射、透射电子显微镜等手段对催化剂进行表征,并利用高活性Pd/CeO_(2)催化剂对2,4-二氯苯氧乙酸(2,4-D)进行液相加氢脱氯反应研究。研究结果表明:载体对催化剂活性影响较大,其中Pd/CeO_(2)催化剂具有高等电点、较强的金属-载体相互作用以及Pd颗粒高分散度的活性特征;Pd/CeO_(2)催化剂对2,4-D的脱氯效果随Pd负载量增加而增加,随pH值的增加呈现先升高后降低的趋势;Pd/CeO_(2)催化剂对2,4-D的加氢脱氯反应符合Langumir-Hinshelwood模型,表明2,4-D在催化剂表面的吸附是反应的速率控制步骤,且Pd/CeO_(2)对不同的污染物都表现出较高的液相加氢还原活性。Palladium catalysts supported on CeO_(2),activated carbon(AC),and SiO_(2)were synthesized by the NaBH4-reduction method.These catalysts were fully characterized using Zeta potential,X-ray diffraction and transmission electron microscope et al.The liquid phase hydrodechlorination of 2,4-dichlorophenoxyacetic acid(2,4-D)was studied with a highly active Pd/CeO_(2)catalyst.The results show that catalyst supports have a great influence on the catalyst activity.The Pd/CeO_(2)catalyst has high isoeleactric point,a stronger metal-support interaction and high Pd particle dispersion.The dehlorination effect of Pd/CeO_(2)catalyst on 2,4-D increases with the increase of Pd loading,and shows a trend of increasing and then decreasing with the increase of pH.The hydrodechlorination of 2,4-D by Pd/CeO_(2)catalyst is consistent with the Langumir-Hinshelwood model,indicating that the catalytic conversion of adsorbed 2,4-D on catalyst surface is the rate controlling step.In addition,Pd/CeO_(2)exhibits a high liquid phase hydrogenation catalytic activity for different contaminants.

关 键 词：液相催化加氢脱氯 2 4-二氯苯氧乙酸 Pd/CeO_(2) NaBH_(4)还原法 

分 类 号：X703.5[环境科学与工程—环境工程]