Integration of mesopores and crystal defects in metal-organic frameworks via templated electrosynthesis

Abstract

Incorporation of mesopores and active sites into metal-organic framework (MOF) materials to uncover new efficient catalysts is a highly desirable but challenging task. We report the first example of a mesoporous MOF obtained by templated electrosynthesis using an ionic liquid as both electrolyte and template. The mesoporous Cu(II)-MOF MFM-100 has been synthesised in 100 seconds at room temperature, and this material incorporates crystal defects with uncoupled Cu(II) centres as evidenced by confocal fluorescence microscopy and electron paramagnetic resonance spectroscopy. MFM-100 prepared in this way shows exceptional catalytic activity for the aerobic oxidation of alcohols to produce aldehydes in near quantitative yield and selectivity under mild conditions, as well as having excellent stability and reusability over repeated cycles. The catalyst-substrate binding interactions have been probed by inelastic neutron scattering. This study offers a simple strategy to create mesopores and active sites simultaneously via electrochemical formation of crystal defects to promote efficient catalysis using MOFs.

Dynamic restructuring of coordinatively unsaturated copper paddle wheel clusters drives CO2 reduction efficiently

“…5 Interest in the reactivity of metal copper and copper based MOFs stems from its unique electrochemistry CO 2 reduction selectivity toward higher-value hydrocarbons beyond CO. [6][7][8][9][10][11][12][13][14][15] Defect engineering in MOFs, such as missing linker defects, has attracted considerable research attention since it offers a means to construct coordinatively unsaturated metal sites, which is generally considered to be the active sites, and thus has important implications for improving the catalytic performance. [16][17][18][19][20][21][22][23] Therefore, constructing coordinatively unsaturated copper paddle wheel in HKSUT-1 may be served to facilitate the catalytic activity. So far, there has been rare report about it.…”

Fundamentals and recent progress relating to the fabrication, functionalization and characterization of mesostructured materials using diverse synthetic methodologies

“…[145][146][147][148][149] Mesoporous catalysts synthesized via in situ oxidation possess remarkable characteristics, such as high surface areas, uniform and large pores, and good mechanical and thermal stabilities, making them favourable for various catalytic applications. [150][151][152][153][154][155][156]…”

Electro-reduction of carbon dioxide at low over-potential at a metal–organic framework decorated cathode

“…2a) 31 . We sought to characterise the nature of the structural defects in Cu 2 (L)-e, which can be captured vividly by confocal fluorescence microscopy (CFM) using the oligomerisation of furfuryl alcohol as a probe 33 . In this case, open Cu(II)-site based defects act as Lewis acid centres that catalyse the formation of oligomers of furfuryl alcohol to generate strong fluorescence.…”

“…2k, l ). The reduction in micropores in Cu 2 (L)-e results in a low N 2 uptake at low pressure, while Cu 2 (L)-e, generated by the template-effect of the ionic liquid during electro-synthesis 33 , shows a total pore volume of 1.89 cm 3 ·g −1 , significantly larger than that of Cu 2 (L)-t (0.32 cm 3 ·g −1 ), reflecting the presence of mesopores in Cu 2 (L)-e. CO 2 adsorption in desolvated Cu 2 (L)-t and Cu 2 (L)-e at 1.0 bar and 298 K are 38.5 and 44.7 cm 3 g −1 , respectively (Fig. 2m ).…”