Chinese Journal of Catalysis ›› 2018, Vol. 39 ›› Issue (4): 693-700.DOI: 10.1016/S1872-2067(17)62937-1

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

Wenyang Fua, Kaifeng Wanga, Xiaoshu Lva, Hailu Fub, Xingan Donga, Ling Chena, Xianming Zhanga, Guangming Jianga   

  1. a Engineering Research Center for Waste Oil Recovery Technology and Equipment, Ministry of Education, Chongqing Technology and Business University, Chongqing 400067, China;
    b College of Quality and Safety Engineering, China Jiliang University, Hangzhou 310018, Zhejiang, China
  • Received:2017-11-20 Revised:2017-12-13 Online:2018-04-18 Published:2018-04-08
  • Contact: 10.1016/S1872-2067(17)62937-1
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (51508055, 51502277), Chongqing Postdoctoral Science Foundation (Xm2016020), and China Postdoctoral Science Foundation (2016M602660), Natural Science Foundation of Chongqing Science and Technology Commission (cstc2016jcyjA0154), and Innovative Research Team of Chongqing (CXTDG201602014).

Abstract:

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 Hads* 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.

Key words: Hydrodechlorination, Electrolysis, Palladium, Titanium nitride, Environmental remediation