Polyoxometalate-based metal–organic coordination networks for heterogeneous catalytic desulfurization. Issue 41 (1st October 2015)

• Record Type: Journal Article
• Authors: Ma, Yuan-Yuan; Tan, Hua-Qiao; Wang, Yong-Hui; Hao, Xiu-Li; Feng, Xiao-Jia; Zang, Hong-Ying; Li, Yang-Guang
• Is Part Of: CrystEngComm. Volume 17:Issue 41(2015)
• Page Start: 7938
• Page End: 7947
• Publication Date: 2015-10-01
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/c5ce01533b
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : Single crystals and nanocrystals of polyoxometalate-based metal-organic coordination networks for heterogeneous catalytic desulfurization. Abstract : Three new polyoxometalate (POM)-based metal–organic coordination networks (MOCNs) with chemical formulae of [Co(BBTZ)1.5 (HBBTZ)(H2 O)2 ][PW12 O40 ]·H2 O (1 ), [Co2.5 (BBTZ)4 (H2 O)2 ] [BW12 O40 ]·4H2 O (2 ) and [Cu(BBTZ)2 ]5 [BW12 O40 ]2 ·4H2 O (3 ) (BBTZ = 1, 4-bis-(1, 2, 4-triazol-1-ylmethyl)benzene) were hydrothermally synthesized in a reaction system containing Keggin-type POMs, transition metal salts (cobalt salts and copper salts) and BBTZ ligands. All compounds were characterized by elemental analyses, IR, powder X-ray diffraction, TG analyses and single-crystal X-ray diffraction analyses. Compound1 exhibits a POM-encapsulated 3-D supramolecular network, while compounds2 and3 display POM-supported 3-D coordination networks. Using the oxidative desulfurization of dibenzothiophene (DBT) as the model, the catalytic activities of compounds1–3 are investigated. All three compounds show efficient catalytic activity for the oxidation of DBT with the order of2 >3 >1 . It is found that the POM species of compounds1–3 play the main role in the catalytic oxidative desulfurization process, while the TM ions, the loading amounts of POMs, and the structural features of these POM-based MOCNs are also necessary factors that affect the catalytic activities. Furthermore, a surfactant-assisted hydrothermal synthesis method has been developed to prepare nanocrystal2 . SEM reveals that the as-synthesized nanocrystalline2 is about 245 nm in diameter. The catalytic oxidative desulfurization experiments show that nanocrystal2 possesses much higher catalytic activities than those of the large single-crystal products of2 .