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.
Department of Environment and Energy, Sejong University, Seoul 05005, Republic of Korea.
Sci Total Environ. 2020 Feb 10;703:134781. doi: 10.1016/j.scitotenv.2019.134781. Epub 2019 Nov 4.
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[Fe(CN)] (CuFeCN) is particularly synthesized and proposed for the first time as a catalyst for reduction of 4-NP in the presence of NaBH. 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 g, 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) 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 and 36.93 min, 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.
普鲁士蓝类似物 (PBA) 作为最经典的配位化合物家族之一，具有多种催化活性，因此被认为是还原 4-硝基苯酚 (4-NP) 为 4-氨基酚 (4-AP) 的有用多相催化剂。然而，尽管 Cu 是一种经过充分验证的用于 4-NP 还原的过渡金属，特别是由于其在温和条件下能够实现反应物的显著转化、环境友好性和高稳定性。然而，尽管 Cu 是一种经过充分验证的用于 4-NP 还原的过渡金属，但从未开发过基于 Cu 的 PBA 并对其进行过彻底研究用于 4-NP 还原。因此，在这项研究中，特别合成了六氰合铁酸铜，Cu[Fe(CN)] (CuFeCN)，并首次提出将其用作在 NaBH 存在下还原 4-NP 的催化剂。CuFeCN 对还原 4-NP 为 4-AP 具有非常高的催化活性，在 4 分钟内转化率达到 100%。在室温下的活性因子 (AF) 为 8057.14 s g，高于所有其他 MFeCN 普鲁士蓝类似物 (M = Co、Fe、Ni、Zn 和 Mn) 的 1 到 2 个数量级。此外，CuFeCN 表现出出色的可重复使用性，在连续 7 个循环中实现了 100%的 4-NP 转化率和高度稳定的速率常数。CuFeCN 催化还原 4-NP 为 4-AP 的活化能 (E) 和 turnover frequency (TOF) 分别确定为 24.6 kJ mol 和 36.93 min，均明显优于文献中大多数报道的催化剂。这些有利的性质使 CuFeCN 成为开发用于水中消除硝基芳烃污染物的有前途的催化剂的理想选择。
