Nitrogen-doped porous carbon-encapsulated copper composite for efficient reduction of 4-nitrophenol

Wenlan Jia; Fuping Tian; Mengjie Zhang; Xinyi Li; Sheng Ye; Yanfu Ma; Wangyin Wang; Yifu Zhang; Changgong Meng; Guang Zeng; Jian Liu

doi:10.1016/j.jcis.2021.03.020

Nitrogen-doped porous carbon-encapsulated copper composite for efficient reduction of 4-nitrophenol

J Colloid Interface Sci. 2021 Jul 15:594:254-264. doi: 10.1016/j.jcis.2021.03.020. Epub 2021 Mar 10.

Authors

Wenlan Jia¹, Fuping Tian², Mengjie Zhang¹, Xinyi Li¹, Sheng Ye³, Yanfu Ma³, Wangyin Wang³, Yifu Zhang¹, Changgong Meng¹, Guang Zeng³, Jian Liu⁴

Affiliations

¹ State Key Laboratory of Fine Chemicals & Department of Chemistry, Dalian University of Technology, 2 Linggong Road, P.O. Box 288, Dalian 116024, China.
² State Key Laboratory of Fine Chemicals & Department of Chemistry, Dalian University of Technology, 2 Linggong Road, P.O. Box 288, Dalian 116024, China. Electronic address: fptian@dlut.edu.cn.
³ State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Science, 568 Zhongshan Road, Dalian 116023, China.
⁴ State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Science, 568 Zhongshan Road, Dalian 116023, China. Electronic address: jianliu@dicp.ac.cn.

PMID: 33765645
DOI: 10.1016/j.jcis.2021.03.020

Abstract

Developing low-cost non-precious metals as efficient catalysts for the reduction of toxic 4-nitrophenol (4-NP) to useful 4-aminophenol (4-AP) have received increasing attention in recent years. Herein, a novel and efficient Cu-based catalyst Cu/Cu_xO@CN (carbon doped with nitrogen) was prepared via a facile method from pyrolysis of bi-ligand MOFs material Cu₂(BDC)₂(BPY) (BDC = p-Phthalic acid, BPY = 4,4'-bipyridyl) in Ar atmosphere. Characterization results revealed that N doping in carbon matrix favors the development of mesoporous structure, the formation of more defect sites in carbon matrix, better dispersion of Cu/Cu_xO nano particles, and maintenance of Cu species in metallic Cu state (the active site), all of which contribute to a superior catalytic activity for 4-NP reduction with a pseudo-first-order rate constant as high as 0.126 s^-1 (the molar ratio of NaBH₄ to 4-NP is 400), nearly 11 times higher than its counterpart Cu/Cu_xO@C without N doping (0.011 s^-1). The activation energy for 4-NP reduction to 4-AP catalyzed by Cu/Cu_xO@CN was determined as 55.6 kJ mol^-1 (the molar ratio of NaBH₄ to 4-NP is 100). In addition, Cu/Cu_xO@CN showed excellent reusability in successive 6 cycles. The facile synthesis and superior catalytic activity make Cu/Cu_xO@CN a promising catalyst in industrial applications for many other similar reaction systems.

Keywords: Bi-ligand MOF Cu(2)(BDC)(2)(BPY); Cu/Cu(x)O@CN; Nitrogen-doped carbon; Reduction of 4-nitrophenol (4-NP).