(2021) Journal of Water Process Engineering_One-step synthesized 3D-structured MOF foam for efficient and convenient catalytic reduction of nitrogen-containing aromatic compounds

Lin J.-Y., Chen P.-Y., Kwon E., Oh W.D., You S., Huang C.-W., Ghanbari F., Wi-Afedzi T., Lin K.-Y.A.

(Elsevier Ltd) Journal of Water Process Engineering ISSN: 22147144 Vol.40 Issue. Article No.101933 DOI: 10.1016/j.jwpe.2021.101933

Metal Organic Frameworks (MOFs) receive increasing attention for 4-nitrophenol (4-NP) reduction; however the existing studies of using MOFs for 4-NP reduction all involve with noble metals. Moreover, the reported MOFs are very fine powders which are inconvenient for realistic implementation. Thus, the present study proposes to develop a MOF foam which exhibits macroscale features of foam and microscale functionalities of MOFs. Specifically, a Cu foam is selected as the macroporous substrate which serves as a porous support and the metal source for synthesizing Cu-based MOF, HKUST-1, via an one-step electrochemical method. The resulting HKUST-1 foam can act as a convenient catalyst for reduction of 4-NP to 4-AP in either batch-type or flow-thru-type reactions. The corresponding activation energy (Ea) of 4-NP reduction (43.3 kJ/mol) is also significantly lower than Ea values of reported catalysts, including noble metal catalysts, whereas the corresponding TOF (48.3 min⁻¹) is higher than many other catalysts. HKUST-1 foam can also efficiently catalyze reduction of methylene blue (MB) to fully decolorize its color. In addition, HKUST-1 foam could be reused over multi-cycles and retain its activity for reduction of 4-NP and MB. These features validate that HKUST-1 foam is a practical, convenient, and reusable catalyst for reduction of 4-NP. © 2021 Elsevier Ltd

This work is supported by the Ministry of Science and Technology (MOST), Taiwan, and financially supported by the “Innovation and Development Center of Sustainable Agriculture” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE), Taiwan.