Palladium nanoparticles assembled on titanium nitride for enhanced electrochemical hydrodechlorination of 2,4-dichlorophenol in water  

金属钯纳米颗粒/氮化钛复合材料对水中2,4-二氯苯酚的电催化氢化脱氯（英文）

作　　者：Wenyang Fu Kaifeng Wang Xiaoshu Lv Hailu Fu Xingan Dong Ling Chen Xianming Zhang Guangming Jiang 付文洋;王开丰;吕晓书;付海陆;董兴安;陈凌;张贤明;蒋光明(重庆工商大学教育部废油资源化技术与装备工程研究中心,重庆400067;中国计量大学质量与安全工程学院,浙江杭州310018)

机构地区：[1]Engineering Research Center for Waste Oil Recovery Technology and Equipment,Ministry of Education,Chongqing Technology and Business University,Chongqing 400067,China [2]College of Quality and Safety Engineering,China Jiliang University,Hangzhou 310018,Zhejiang,China

出　　处：《Chinese Journal of Catalysis》2018年第4期693-700,共8页催化学报（英文）

基　　金：supported by the National Natural Science Foundation of China(51508055,51502277);Chongqing Postdoctoral Science Foundation(Xm2016020);China Postdoctoral Science Foundation(2016M602660);Natural Science Foundation of Chongqing Science and Technology Commission(cstc2016jcyjA0154);Innovative Research Team of Chongqing(CXTDG201602014)~~

摘　　要：We report a one‐pot surfactant‐free wet‐chemical reduction approach to the synthesis of palladium/titanium nitride(Pd/TiN)and Pd/carbon(Pd/C)composites,in which^5 nm Pd NPs were uniformly dispersed on TiN or C.In terms of catalytic performance,Pd/TiN showed enhanced efficiency and stability compared with those of Pd/C and bare TiN in the electrocatalytic hydrodechlorination(EHDC)reaction of 2,4‐dichlorophenol(2,4‐DCP)in aqueous solution.The superior performance of Pd/TiN arises from the promotion effect of TiN.Strong metal‐support interactions modified the electronic structure of Pd,which optimized generation of H*ads and 2,4‐DCP adsorption/activation.The cathode potential plays a vital role in controlling the EHDC efficiency and the product distribution.A working potential of?0.80 V was shown to be optimal for achieving the highest EHDC efficiency and maximizing conversion of 2,4‐DCP to phenol(P).Our studies of the reaction pathway show that EHDC of 2,4‐DCP on Pd/TiN proceeded by 2,4‐DCP→p‐chlorophenol(p‐CP),o‐chlorophenol(o‐CP)→P;however,Pd/TiN presented little selectivity for cleavage of p‐C‐Cl vs o‐C‐Cl.This work presents a new approach to enhancing Pd performance towards EHDC through the effects of a support.The strategy demonstrated here could also be extended to design highly efficient catalysts for other hydrogenation reactions.随着社会经济的快速发展,含氯有机物,特别是含氯苯系物,在农业、化工和医药等领域的使用量逐年增多,而使用过程中不合理的排放和控制致使含氯苯系物对生态环境,特别是水体环境的污染日趋严重.含氯苯系物具有高致毒致癌性,易生物富集,且很难被完全降解矿化,已被国家环保局认定为优先控制污染物.常规的废水处理工艺,如吸附、氧化及生物降解等,效率不高,且具有二次污染风险.电催化氢化脱氯技术是一种新型特别针对废水中含氯有机污染物的处理工艺,是通过在阴极电解还原水,原位生成原子态氢,以进攻苯环上C.Cl键,通过C.Cl键断裂H原子取代,使含氯苯系物完全转化为苯系物,达到去毒去害化的目的,近年来越来越受到研究者的关注.在整个电催化氢化脱氯技术中,高效稳定的电催化剂合成是关键,决定着脱氯效率、脱氯动力学、产物选择性及能量的利用率.本文报道了一种简易、无需添加任何表面活性剂的湿式还原法制备金属钯/氮化钛(Pd/TiN)和金属钯/碳(Pd/C)复合材料.在该复合材料中,金属钯颗粒具有均一的纳米尺寸(约5.0 nm)和球状形貌,且均匀分布在TiN和C载体上.作为针对水体中代表性含氯苯系物2,4-二氯苯酚的电催化氢化脱氯反应催化剂,Pd/TiN所展现的活性和稳定性均优于TiN和Pd/C,这源于TiN载体的促进作用.当TiN与Pd复合时,相应形成的Pd-TiN界面可改变Pd表面的电子结构,进一步优化Pd产活性氢及其吸附活化2,4-二氯苯酚的性能,因而其催化氢化脱氯活性增加.阴极工作电压是该催化反应中一个重要操作参数,决定了电催化氢化脱氯的效率和最终产物的构成.实验表明,.0.80 V vs Ag/AgCl是最佳操作电压,此时2,4-二氯苯酚的电催化氢化脱氯效率最高,可达到93.27%,且可实现最大程度的2,4-二氯苯酚向苯酚转化.脱氯反应路径研究发现,在Pd/TiN催化剂上2,4-二氯苯酚�

关 键 词：HYDRODECHLORINATION ELECTROLYSIS PALLADIUM Titanium nitride Environmental remediation 

分 类 号：O643.3[理学—物理化学] X703[理学—化学]