Three novel Co(II)-MOFs with a conjugated tetrabenzoic acid supported noble metal nanoparticles for efficient catalytic reduction of 4-nitrophenol

• Published in: Journal of solid state chemistry 2022-03, Vol.307, p.122867, Article 122867
• Main Authors: Guo, Gui-Zhi, Xi, Ben-Jun, Li, Yong-Shuang, Chang, Xi-Wen, Luo, Jia-Yang, Wang, Bin, Wu, Xue-Qian, Wu, Ya-Pan, Li, Dong-Sheng
• Format: Article
• Language: English
• Subjects: Composite; Crystal structure; Heterogeneous catalysis; MOFs
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2021.122867

The utilization of porous metal-organic frameworks (MOFs) as catalyst support has attracted intensive attentions in heterogeneous catalysis. However, the study of structure-activity relationship in this confined catalysis system is still scarce. Herein, three isostructural Co(II)-MOFs {Co2L(bpy)}n (CTGU-11), {Co2L(bpe)}n (CTGU-12) and {Co2L(bib)}n (CTGU-13) were synthesized by using 4,4′,4″,4‴-(1,3,6,8-Pyrenetetrayl)tetrabenzoic acid (H4L) as an organic ligand, and introducing three N-donor ligands (bpy ​= ​4,4′-dipyridyl, bpe ​= ​1,2-di(4-pyridyl)ethylene, bib ​= ​1,4-bis(1-imidazoly)benzene) with different length. Among these Co(II)-MOFs, each L4− anion bridges four typical paddle wheel secondary building units (SBUs) to form a two dimensional (2D) sheet, which further expanded to the three-fold interpenetrated structure with the aid of different pillared ligands. Inspired by the eligible structure/surface feature of these frameworks, a series of Co-MOF-supported heterogeneous catalysts (NM@Co-MOFs, NM = Ag, Ru, Pd and Au) have been fabricated successfully via solution infiltration, for the reduction of 4-nitrophenol (4NP). Impressively, 2-Ru@Co-MOFs exhibit remarkable activity in comparison to other NM@Co-MOFs composites with the apparent rate constant reach 50.72 ​s-1 ​g-1, 26.14 ​s-1 ​g-1, and 22.79 ​s-1 ​g-1, respectively. Furthermore, the possible catalytic mechanism of 2-Ru@Co-MOFs has also been discussed based on the analysis of reaction kinetics. Three isostructural Co(II)-MOFs were synthesized by using a conjugated tetrabenzoic acid(H4L) as an organic ligand, and introducing three N-donor ligands with different length. Among these Co(II)-MOFs, each L4− anion bridges four typical paddle wheel secondary building units (SBUs) to form a two dimensional (2D) sheet, which further expanded to the three-fold interpenetrated structure with the aid of different pillared ligands. Inspired by the eligible structure/surface feature of these frameworks, a series of Co-MOF-supported heterogeneous catalysts (NM@Co-MOFs, NM = Ag, Ru, Pd and Au) have been fabricated successfully via solution infiltration, for the reduction of 4-nitrophenol. [Display omitted] •Three novel isostructural 3D Co(II)-MOFs have been prepared.•The integration metal nanoparticles into MOFs shows positive effect on reduction of 4-NP.•The electronic effects between noble metal and MOFs accelerate catalytic process.