Crystallinity after decarboxylation of a metal–carboxylate framework: indestructible porosity for catalysis. Issue 34 (18th August 2020)

• Record Type: Journal Article
• Authors: Cheng, Shengxian; Tieu, Peter; Gao, Wenpei; Hu, Jieying; Feng, Weijin; He, Jun; Pan, Xiaoqing; Xu, Zhengtao
• Is Part Of: Dalton transactions. Volume 49:Issue 34(2020)
• Page Start: 11902
• Page End: 11910
• Publication Date: 2020-08-18
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt02075c
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Towards 3D graphene: cyclizing the polyalkyne linkers of a Zr(iv )-based coordination network leads to an ordered carbon framework for versatile catalysis. Abstract : We report a curious case study of a Zr(iv )-carboxylate framework, which retains significant crystalline order after cascade thermocyclization of its linker components, and – more notably – after the crucial carboxylate links were severed by heat. Vigorous heat treatment ( e.g., 450 °C and above) benzannulates the multiple alkyne groups on the linker to generate linked nanographene blocks and to afford real stability. The resultant Zr oxide/nanographene hybrid solid is stable in saturated NaOH and concentrated H3 PO4, allowing a convenient anchoring of H3 PO4 into its porous matrix to enable size-selective heterogeneous acid catalysis. The Zr oxide components can also be removed by strong hydrofluoric acid to further enhance the surface area (up to 650 m 2 g −1 ), without collapsing the nanographene scaffold. The crystallinity order and the extensive thermal transformations were characterized by X-ray diffraction, scanning transmission electron microscopy (STEM), IR, solid state NMR and other instrumental methods.