Metal–Organic Framework-Derived Electrocatalysts Competent for the Conversion of Acrylonitrile to Adiponitrile

Abstract

Electrochemical conversion of acrylonitrile (AN) to produce adiponitrile (ADN), the raw material for the production of Nylon 66, has become a crucial process owing to the increasing market demand of Nylon 66. Although the metallic Pb or Cd electrodes are commonly used for this reaction, the use of electrocatalysts or electrodes modified with catalysts has been barely investigated. In this study, nanoporous and electrically conductive metal–organic framework (MOF)-derived materials composed of Pb, PbO, and carbon are synthesized by carbonizing a Pb-based MOF through thermal treatments, and these MOF-derived materials are served as electrocatalysts for the electrosynthesis of ADN. The crystallinity, morphology, elemental composition, porosity, electrical conductivity, and electrochemically active surface area of each MOF-derived material are investigated. Mass-transport-corrected Tafel analysis is used to probe the enhanced kinetics for the electrochemical reduction of AN occurring at the electrode modified with the MOF-derived material. Electrolytic experiments at various applied potentials are conducted to quantify the production rate and Faradaic efficiency toward ADN, and the result shows that the MOF-derived materials can act as electrocatalysts to initiate the electrochemical reduction of AN to produce ADN at a reduced overpotential. The optimal MOF-derived electrocatalyst can achieve a Faradaic efficiency of 67% toward ADN at an applied potential of −0.85 V versus reversible hydrogen electrodea much lower overpotential compared to that typically required for this reaction without the use of catalysts. Findings here shed light on the design and development of advanced electrocatalysts to boost the performances for the electrosynthesis of ADN.

Cerium(IV)-Based Metal–Organic Framework Nanostructures Grown on 3D-Printed Free-Standing Membranes and Their Derivatives for Charge Storage

“…Grazing incidence X-ray diffraction (GIXRD) data of all membranes were collected by using a Bruker D8 Discover. Information regarding other instruments used for characterizing materials including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared (FTIR) spectroscopy, inductively coupled plasma-optical emission spectroscopy (ICP-OES), and Raman spectroscopy can be found in our previous work. , For ICP-OES measurements, one Ce-MOF/CNC@PAAm membrane with a mass of around 10 mg was accurately weighted before being digested in the mixture containing 0.75 mL of H 2 SO 4 and 0.25 mL of H 2 O 2 at 150 °C for 1 h by using an initiator+ microwave heater (Biotage). The resulting mixture was filtered by a 200 nm syringe filter, and the filtrate was diluted to 40 mL by 3% HNO 3 (aq) to obtain the ICP-OES sample.…”

“…Before recording the electrochemical data, 30 cycles of CV scan between 0 and +0.8 V [vs Ag/AgCl/NaCl (3 M)] at a scan rate of 25 mV/s was first performed to stabilize the working electrode. For measuring the electrical conductivity of each material, the MOF-derived ceria/CM was ground into fine powder and pelletized, and the two-probe method was utilized to quantify the electrical conductivity of the Ce-MOF/CNC@PAAm membrane and each pelletized material, by using the same CHI6273E; see experimental details reported in our previous work. ,, …”

“…For measuring the electrical conductivity of each material, the MOFderived ceria/CM was ground into fine powder and pelletized, and the two-probe method was utilized to quantify the electrical conductivity of the Ce-MOF/CNC@PAAm membrane and each pelletized material, by using the same CHI6273E; see experimental details reported in our previous work. 25,26,55 3. RESULTS AND DISCUSSION 3.1.…”

“…The heating process at a temperature equal to or higher than 800 °C is required to achieve a sufficient degree of carbonization and a high electrical conductivity; a similar finding has been reported for other MOF-derived materials as well. 55 Since all the MOF-derived free-standing membranes prepared here are electrically conductive, and their carbon and ceria are expected to exhibit the double-layer capacitance and pseudocapacitance in aqueous electrolytes, respectively, 49,50,65 as a demonstration here, these MOF-derived membranes were utilized as the free-standing electrodes to test their capacitive performances. It should be noted that since the CeO x /CM-1000 revealed serious swelling and deformation after the carbonization (Figure S2), which made it difficult to obtain reliable and reproducible electrochemical data, only the capacitive behaviors of CeO x /CM-700, CeO x /CM-800, and CeO x /CM-900 were examined.…”

Multidimensional MOF-derived carbon nanomaterials for multifunctional applications

“…13k). 177 The available Pd/PdO composite can efficiently convert acrylonitrile (AN) to adiponitrile (ADN) electrochemically, with an AN reduction efficiency of 67% at a low overpotential. In this case, MOF-derived 2D films have better adhesion to the substrate and show great industrial application space.…”