Copper hexacyanoferrate nanocrystal as a highly efficient non-noble metal catalyst for reduction of 4-nitrophenol in water

Thomas Wi-Afedzi; Eilhann Kwon; Duong Dinh Tuan; Kun-Yi Andrew Lin; Farshid Ghanbari

doi:10.1016/j.scitotenv.2019.134781

Copper hexacyanoferrate nanocrystal as a highly efficient non-noble metal catalyst for reduction of 4-nitrophenol in water

Sci Total Environ. 2020 Feb 10:703:134781. doi: 10.1016/j.scitotenv.2019.134781. Epub 2019 Nov 4.

Authors

Thomas Wi-Afedzi¹, Eilhann Kwon², Duong Dinh Tuan¹, Kun-Yi Andrew Lin³, Farshid Ghanbari⁴

Affiliations

¹ Department of Environmental Engineering & Innovation and Development Center of Sustainable Agriculture & Research Center of Sustainable Energy and Nanotechnology, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan.
² Department of Environment and Energy, Sejong University, Seoul 05005, Republic of Korea.
³ Department of Environmental Engineering & Innovation and Development Center of Sustainable Agriculture & Research Center of Sustainable Energy and Nanotechnology, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan. Electronic address: linky@nchu.edu.tw.
⁴ Department of Environmental Health Engineering, Abadan School of Medical Sciences, Abadan, Iran. Electronic address: Ghanbari.env@gmail.com.

PMID: 31744698
DOI: 10.1016/j.scitotenv.2019.134781

Abstract

As Prussian Blue analogues (PBAs) represent one of the most classical families of coordination compounds and exhibit versatile catalytic activities, PBAs have been considered as useful heterogeneous catalysts for reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Nevertheless, while Cu has been a well-proven transition metal for 4-NP reduction, especially, due to their ability to attain pronounced conversions of reactants under mild conditions, environmental friendliness and great stability. Nevertheless, while Cu has been a well-proven transition metal for 4-NP reduction, Cu-based PBA has never been developed and thoroughly investigated for 4-NP reduction. Thus, in this study, copper hexacyanoferrate, Cu^II₃[Fe(CN)₆]₂ (CuFeCN) is particularly synthesized and proposed for the first time as a catalyst for reduction of 4-NP in the presence of NaBH₄. CuFeCN exhibits a very high catalytic activity towards reduction of 4-NP to 4-AP with 100% conversion within 4 min. The activity factor (AF) at room temperature, 8057.14 s^-1 g^-1, is between 1 and 2 orders higher than all other MFeCN Prussian blue analogues (M = Co, Fe, Ni, Zn, and Mn). In addition, CuFeCN shows excellent reusability to achieve 100% conversion of 4-NP to 4-AP with highly stable rate constants over successive 7 cycles. The activation energy (E_a) and turn over frequency (TOF) for the reduction of 4-NP to 4-AP catalyzed by CuFeCN system are determined as 24.6 kJ mol^-1 and 36.93 min^-1, respectively, which are both significantly more superior than most of reported catalysts in literatures. These advantageous properties make CuFeCN ideal to be developed into a promising catalyst for elimination of nitroaromatic contaminants in water.

Keywords: 4-Aminophenol; 4-Nitrophenol; Activation energy; Catalytic activity; Prussian blue analogue; Reduction; Sodium borohydride; Turn over frequency.