Copper(II) tetrakis(pentafluorophenyl)porphyrin: Highly Active Copper-based Molecular Catalyst for Electrochemical CO2 Reduction

2022 ◽  
Author(s):  
Kento Kosugi ◽  
Hina Kashima ◽  
Mio Kondo ◽  
Shigeyuki Masaoka

We report a highly active copper-based catalyst for electrochemical CO2 reduction. Electrochemical analysis revealed that the maximum turnover frequency for CO2 to CO conversion reached to 1,460,000 s-1 at an...

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5524
Author(s):  
Kirill V. Kholin ◽  
Mikhail N. Khrizanforov ◽  
Vasily M. Babaev ◽  
Guliya R. Nizameeva ◽  
Salima T. Minzanova ◽  
...  

A selective noble-metal-free molecular catalyst has emerged as a fruitful approach in the quest for designing efficient and stable catalytic materials for CO2 reduction. In this work, we report that a sodium pectate complex of copper (PG-NaCu) proved to be highly active in the electrocatalytic conversion of CO2 to CH4 in water. Stability and selectivity of conversion of CO2 to CH4 as a product at a glassy carbon electrode were discovered. The copper complex PG-NaCu was synthesized and characterized by physicochemical methods. The electrochemical CO2 reduction reaction (CO2RR) proceeds at −1.5 V vs. Ag/AgCl at ~10 mA/cm2 current densities in the presence of the catalyst. The current density decreases by less than 20% within 12 h of electrolysis (the main decrease occurs in the first 3 h of electrolysis in the presence of CO2). This copper pectate complex (PG-NaCu) combines the advantages of heterogeneous and homogeneous catalysts, the stability of heterogeneous solid materials and the performance (high activity and selectivity) of molecular catalysts.


2020 ◽  
Author(s):  
Matthias Wessling

As a remedy to the increasing concentration of greenhouse gases and depleting fossil resources, the electrochemical CO2 reduction closes the carbon cycle and provides an alternative carbon feedstock to the chemical and energy industry. While most contemporary research focuses on the catalyst activity, we emphasize the importance of the reactor design for an energetic efficient (EE) conversion. A design strategy for an electrochemical membrane reactor reducing CO2 to hydrogen, carbon monoxide (CO) and ethylene (C2H4) is developed. We present the stepwise development from an H-cell like setup using full-metal electrodes to a cell with gas diffusion electrodes (GDE) towards high current efficiencies (CE) at high current densities (CD). At 300 mA.cm−2 a CO-CE of 56% for a Ag GDE and a C2H4-CE of 94% for a Cu GDE are measured. The incorporation of the developed GDEs into a zero-gap assembly eliminates ohmic losses and maximizes EE, however the acidic environment of the ion exchange membrane inhibits CO2 reduction. As a compromise a thin liquid buffer layer between cathode and membrane is a prerequisite for a highly active conversion. We demonstrate that industrial relevant CDs with high CEs and EEs can only be achieved by moving beyond today’s research form catalyst development only to an integrated reactor design, which allows to exploit the viable potential of electrochemical CO2 reduction catalysts.


2020 ◽  
Vol 3 (10) ◽  
pp. 804-812 ◽  
Author(s):  
Chungseok Choi ◽  
Soonho Kwon ◽  
Tao Cheng ◽  
Mingjie Xu ◽  
Peter Tieu ◽  
...  

2015 ◽  
Vol 183 ◽  
pp. 147-160 ◽  
Author(s):  
James J. Walsh ◽  
Charlotte L. Smith ◽  
Gaia Neri ◽  
George F. S. Whitehead ◽  
Craig M. Robertson ◽  
...  

Immobilization of [Mn(bpy)(CO)3Br], (1) and [Mn(bpy(tBu)2)(CO)3Br] (2, where (bpy(tBu)2) = 4,4′-di-tert-butyl-2,2′-bipyridine) in Nafion/multi-walled carbon nanotubes (MWCNT) on glassy carbon yielded highly active electrodes for the reduction of CO2 to CO in aqueous solutions at pH 7. Films incorporating 2 have significantly improved selectivity towards CO2, with CO : H2 ∼ 1 at −1.4 V vs. SCE, exceeding that for the previously reported 1/MWCNT/Nafion electrode. Furthermore, we report the synthesis and subsequent electrochemical characterization of two new substituted Mn(i) bipyridine complexes, [Mn(bpy(COOH)2)(CO)3Br] (3) and [Mn(bpy(OH)2)(CO)3Br] (4) (where (bpy(COOH)2) = 4,4′-di-carboxy-2,2′-bipyridine and (bpy(OH)2) = 4,4′-di-hydroxy-2,2′-bipyridine). Both 3 and 4 were found to have some activity towards CO2 in acetonitrile solutions; however once immobilized in Nafion membranes CO2 reduction was found to not occur at significant levels.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 535
Author(s):  
Shuaikang Zhu ◽  
Xiaona Ren ◽  
Xiaoxue Li ◽  
Xiaopo Niu ◽  
Miao Wang ◽  
...  

The copper-based catalyst is considered to be the only catalyst for electrochemical carbon dioxide reduction to produce a variety of hydrocarbons, but its low selectivity and low current density to C2 products restrict its development. Herein, a core-shell xZnO@yCu2O catalysts for electrochemical CO2 reduction was fabricated via a two-step route. The high selectivity of C2 products of 49.8% on ZnO@4Cu2O (ethylene 33.5%, ethanol 16.3%) with an excellent total current density of 140.1 mA cm−2 was achieved over this core-shell structure catalyst in a flow cell, in which the C2 selectivity was twice that of Cu2O. The high electrochemical activity for ECR to C2 products was attributed to the synergetic effects of the ZnO core and Cu2O shell, which not only enhanced the selectivity of the coordinating electron, improved the HER overpotential, and fastened the electron transfer, but also promoted the multielectron involved kinetics for ethylene and ethanol production. This work provides some new insights into the design of highly efficient Cu-based electrocatalysts for enhancing the selectivity of electrochemical CO2 reduction to produce high-value C2 products.


Author(s):  
Peter T. Smith ◽  
Sophia Weng ◽  
Christopher Chang

We present a bioinspired strategy for enhancing electrochemical carbon dioxide reduction catalysis by cooperative use of base-metal molecular catalysts with intermolecular second-sphere redox mediators that facilitate both electron and proton transfer. Functional synthetic mimics of the biological redox cofactor NADH, which are electrochemically stable and are capable of mediating both electron and proton transfer, can enhance the activity of an iron porphyrin catalyst for electrochemical reduction of CO<sub>2</sub> to CO, achieving a 13-fold rate improvement without altering the intrinsic high selectivity of this catalyst platform for CO<sub>2</sub> versus proton reduction. Evaluation of a systematic series of NADH analogs and redox-inactive control additives with varying proton and electron reservoir properties reveals that both electron and proton transfer contribute to the observed catalytic enhancements. This work establishes that second-sphere dual control of electron and proton inventories is a viable design strategy for developing more effective electrocatalysts for CO<sub>2</sub> reduction, providing a starting point for broader applications of this approach to other multi-electron, multi-proton transformations.


Sign in / Sign up

Export Citation Format

Share Document