Preparation of Nickel Nanocatalysts and Application to the Hydrodechlorination of 3-Chlorophenol under Liquid Phase

Thanh Thien Co,Thi Kim Anh Tran,Thi Duyen Diep,Thi Huong Ly Doan,Suresh Kannan Balasingam

doi:10.1155/2021/8580754

Abstract

Nickel nanoparticles were successfully synthesized via the reduction of nickel salt using ethylene glycol (EG) and sodium borohydride (NaBH4) as reducing agents. These nickel nanoparticles were then loaded on the supports as Ni-X (X = vanadium phosphorus oxides (VPO), TiO2, and ZnO) in high loading yield. The optical properties of these catalysts were characterized by UV-vis spectroscopy, the structure of Ni-X was studied by powder X-ray diffraction (PXRD), the distribution of Ni particles in X was studied by transmission electron microscopy (TEM), and the specific surface area of Ni-X was evaluated by N2 adsorption isotherm analysis at 77 K. All results corroborated the loading process. Indeed, TEM image indicated that the nickel nanoparticles size is in the range of 14 ÷ 16 nm and fully loaded into X. The activities of these catalysts were performed on the hydrodechlorination of 3-chlorophenol in the presence of sodium hydroxide as base at atmospheric pressure and at RT. The results showed that Ni-X exhibited high activities up to 98% within 90 min in the case of Ni-ZnO catalyst.

Highlights

Every year, hundreds of chemical plants in the world produce tens of millions of tons of chlorine derivatives and large amounts of sodium hydroxide to serve for the industrial production according to the World Chlorine Council [1]
Nickel nanoparticles were synthesized by the reduction of NiCl2.6H2O using ethylene glycol (EG) and NaBH4 as reduction agents. e original blue solution was turned dark when Ni0 nanoparticles formed. e reason EG and NaBH4 were used is that EG reduction is a common process for the preparation of metal nanoparticles, yet this process needs to be assisted by high temperature or microwave irradiation to improve the reduction performance [16, 17]
Sodium borohydride is considered as a force reducing agent which can reduce metallic ions at room temperature, and the disadvantage of sodium borohydride process is the formation of irregular particle size [18]

Summary

Introduction

Hundreds of chemical plants in the world produce tens of millions of tons of chlorine derivatives and large amounts of sodium hydroxide to serve for the industrial production according to the World Chlorine Council [1]. E oxidative degradation, biological decomposition, and hydrodechlorination were considered as alternative methods of removing large amounts of organic pollutants in which the hydrodechlorination method promises high efficiency and safety and gives a beneficial product in industry. One of the useful methods to hydrodechlorinate chlorine derivatives is using nanomaterials because of the low cost and easy to control the process. Xia et al reported the hydrodechlorination of monochlorophenol with palladium nanoparticles supported on activated carbon as catalyst, and the conversion of chlorine substrates reached over 99% within 50 min reaction [9]. Xu and coworkers presented the nickel nanoparticles which supported low concentration on titanium dioxide as the support and used as a catalyst for the hydrodechlorination of chlorobenzene at 573 K, and the catalyst exhibited excellent stability compared to other catalysts [14]

Methods

Results

Conclusion