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

Abstract Electrochemical reduction of carbon dioxide is a clean and highly attractive strategy for the production of organic products. However, this is hindered severely by the high negative potential required to activate carbon dioxide. Here, we report the preparation of a copper-electrode onto which the porous metal–organic framework [Cu2(L)] [H4L = 4,4′,4″,4′′′-(1,4-phenylenebis(pyridine-4,2,6-triyl))tetrabenzoic acid] can be deposited by electro-synthesis templated by an ionic liquid. This decorated electrode shows a remarkable onset potential for reduction of carbon dioxide to formic acid at −1.45 V vs. Ag/Ag+, representing a low value for electro-reduction of carbon dioxide in an organic electrolyte. A current density of 65.8 mA·cm−2 at −1.8 V vs. Ag/Ag+ is observed with a Faradaic efficiency to formic acid of 90.5%. Electron paramagnetic resonance spectroscopy confirms that the templated electro-synthesis affords structural defects in the metal–organic framework film comprising uncoupled Cu(II) centres homogenously distributed throughout. These active sites promote catalytic performance as confirmed by computational modelling.

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.

Synthesis of Hierarchical Porous Metals Using Ionic‐Liquid‐Based Media as Solvent and Template

Synthesis of hierarchical mesoporous Prussian blue analogues in ionic liquid/water/MgCl2 and application in electrochemical reduction of CO2

Hierarchical mesoporous Prussian blue analogues synthesized in ionic liquid/water/MgCl2 systems were used as efficient electrodes for electroreduction of CO2.

Synthesis of hierarchical porous β-FeOOH catalysts in ionic liquid/water/CH2Cl2 ionogels

The ionic liquid/water/CH2Cl2 ionogels were created and were used to synthesize highly efficient heterogeneous hierarchical porous β-FeOOH catalysts.

Formation of large nanodomains in liquid solutions near the phase boundary

Large nanodomains were formed in liquid solutions near the phase separation point where the size of nanodomains increased dramatically.

Highly efficient electrochemical reduction of CO2 to CH4 in an ionic liquid using a metal–organic framework cathode

It has been discovered that Zn metal-organic framework (Zn-MOF) electrodes and ionic liquids are an excellent combination for the efficient and selective reduction of CO2 to CH4.

Synthesis of Functional Nanomaterials in Ionic Liquids

Synthesis of Supported Ultrafine Non-noble Subnanometer-Scale Metal Particles Derived from Metal-Organic Frameworks as Highly Efficient Heterogeneous Catalysts

Mesoporous inorganic salts with crystal defects: unusual catalysts and catalyst supports

Mesoporous LaF3, NdF3, and YF3 particles with crystal defects, which are excellent catalysts and catalyst supports, have been synthesized successfully.

One-Step Synthesis of Highly Efficient Nanocatalysts on the Supports with Hierarchical Pores Using Porous Ionic Liquid-Water Gel