scholarly journals Promoting Photocatalytic CO2 Reduction Through Facile Electronic Modification of N-Annulated Perylene Diimide Rhenium Bipyridine Dyads

2022 ◽  
Author(s):  
Gregory Charles Welch ◽  
Josh Koenig ◽  
Warren Piers
Keyword(s):  
Co2 Reduction ◽  
Perylene Diimide ◽  
Co2 Conversion

The development of CO2 conversion catalysts has become paramount in the effort to close the carbon loop. Herein, we report the synthesis, characterization, and photocatalytic CO2 reduction performance for a...

scholarly journals Electron-Reservoir Effect on a Perylene Diimide Tethered Rhenium Bipyridine Complex for CO2 Reduction

2020 ◽  
Author(s):  
Josh D. B. Koenig ◽  
Zachary Dubrawski ◽  
Keerthan Rao ◽  
Janina Willkomm ◽  
Benjamin S. Gelfand ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Density Functional ◽  
Chemical Reduction ◽  
Critical Role ◽  
Co2 Reduction ◽  
Perylene Diimide ◽  
Co2 Conversion ◽  
Faradaic Efficiency ◽  
Molecular Catalyst ◽  
Controlled Potential

Here we report on a molecular catalyst with a built-in electron-reservoir for enhanced CO2 conversion. The synthesis and characterization of this N-annulated perylene diimide (PDI) photosensitized Re(bpy) supramolecular dyad [Re(bpy-TAz-PDI)], as well as successful electro- and photocatalytic CO2-to-CO conversion, are detailed herein. Upon electrochemical reduction in the presence of CO2 and a proton source, Re(bpy-TAz-PDI) exhibited significant current enhancement, where the onset of electrocatalytic CO2 reduction for Re(bpy-TAz-PDI) occurred at a much less negative potential than standard Re(bpy) complexes. At an applied potential of -1.8 V vs. Fc+/0, 400 mV lower than the benchmark Re(dmbpy) catalyst, Re(bpy-TAz-PDI) was able to achieve the same catalytic activity (TONco = 24) and Faradaic efficiency (FE = 92 %) during controlled potential electrolysis (CPE) experiments. Through a combination of UV-visible-nearIR spectroelectrochemistry (SEC), FTIR SEC, and chemical reduction experiments, it was shown that the PDI-moiety served as an electron-reservoir for Re(bpy), thereby allowing catalytic activity at lower overpotentials. Density functional theory (DFT) studies probing the optimized geometries, frontier molecular orbitals, and spin-densities of various catalytic intermediates revealed that the geometric configuration of PDI, relative to the Re(bpy)-moiety, plays a critical role in accessing electrons from the electron-reservoir. The near identical performance of Re(bpy-TAz-PDI) at lower overpotentials relative to the benchmark Re(dmbpy) catalyst highlights the utility of organic chromophore electron-reservoirs as a method for lowering the required overpotential for CO2 conversion. <br>

scholarly journals Electron-Reservoir Effect on a Perylene Diimide Tethered Rhenium Bipyridine Complex for CO2 Reduction

2020 ◽  
Author(s):  
Josh D. B. Koenig ◽  
Zachary Dubrawski ◽  
Keerthan Rao ◽  
Janina Willkomm ◽  
Benjamin S. Gelfand ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Density Functional ◽  
Chemical Reduction ◽  
Critical Role ◽  
Co2 Reduction ◽  
Perylene Diimide ◽  
Co2 Conversion ◽  
Faradaic Efficiency ◽  
Molecular Catalyst ◽  
Controlled Potential

Here we report on a molecular catalyst with a built-in electron-reservoir for enhanced CO2 conversion. The synthesis and characterization of this N-annulated perylene diimide (PDI) photosensitized Re(bpy) supramolecular dyad [Re(bpy-TAz-PDI)], as well as successful electro- and photocatalytic CO2-to-CO conversion, are detailed herein. Upon electrochemical reduction in the presence of CO2 and a proton source, Re(bpy-TAz-PDI) exhibited significant current enhancement, where the onset of electrocatalytic CO2 reduction for Re(bpy-TAz-PDI) occurred at a much less negative potential than standard Re(bpy) complexes. At an applied potential of -1.8 V vs. Fc+/0, 400 mV lower than the benchmark Re(dmbpy) catalyst, Re(bpy-TAz-PDI) was able to achieve the same catalytic activity (TONco = 24) and Faradaic efficiency (FE = 92 %) during controlled potential electrolysis (CPE) experiments. Through a combination of UV-visible-nearIR spectroelectrochemistry (SEC), FTIR SEC, and chemical reduction experiments, it was shown that the PDI-moiety served as an electron-reservoir for Re(bpy), thereby allowing catalytic activity at lower overpotentials. Density functional theory (DFT) studies probing the optimized geometries, frontier molecular orbitals, and spin-densities of various catalytic intermediates revealed that the geometric configuration of PDI, relative to the Re(bpy)-moiety, plays a critical role in accessing electrons from the electron-reservoir. The near identical performance of Re(bpy-TAz-PDI) at lower overpotentials relative to the benchmark Re(dmbpy) catalyst highlights the utility of organic chromophore electron-reservoirs as a method for lowering the required overpotential for CO2 conversion. <br>

scholarly journals Investigation of Gas Diffusion Electrode Systems for the Electrochemical CO2 Conversion

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 482
Author(s):  
Hilmar Guzmán ◽  
Federica Zammillo ◽  
Daniela Roldán ◽  
Camilla Galletti ◽  
Nunzio Russo ◽  
...  
Keyword(s):  
Carbon Capture ◽  
Active Sites ◽  
Co2 Reduction ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Catalyst Loading ◽  
Co2 Conversion ◽  
Atmospheric Conditions ◽  
Electrochemical Co2 Reduction ◽  
Liquid Products

Electrochemical CO2 reduction is a promising carbon capture and utilisation technology. Herein, a continuous flow gas diffusion electrode (GDE)-cell configuration has been studied to convert CO2 via electrochemical reduction under atmospheric conditions. To this purpose, Cu-based electrocatalysts immobilised on a porous and conductive GDE have been tested. Many system variables have been evaluated to find the most promising conditions able to lead to increased production of CO2 reduction liquid products, specifically: applied potentials, catalyst loading, Nafion content, KHCO3 electrolyte concentration, and the presence of metal oxides, like ZnO or/and Al2O3. In particular, the CO productivity increased at the lowest Nafion content of 15%, leading to syngas with an H2/CO ratio of ~1. Meanwhile, at the highest Nafion content (45%), C2+ products formation has been increased, and the CO selectivity has been decreased by 80%. The reported results revealed that the liquid crossover through the GDE highly impacts CO2 diffusion to the catalyst active sites, thus reducing the CO2 conversion efficiency. Through mathematical modelling, it has been confirmed that the increase of the local pH, coupled to the electrode-wetting, promotes the formation of bicarbonate species that deactivate the catalysts surface, hindering the mechanisms for the C2+ liquid products generation. These results want to shine the spotlight on kinetics and transport limitations, shifting the focus from catalytic activity of materials to other involved factors.

scholarly journals Improving the Catalytic CO2 Reduction on Cs2AgBiBr6 by Halide Defect Engineering: A DFT Study

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2469
Author(s):  
Pengfei Chen ◽  
Yiao Huang ◽  
Zuhao Shi ◽  
Xingzhu Chen ◽  
Neng Li
Keyword(s):  
Gas Adsorption ◽  
Catalytic Reduction ◽  
Deep Level ◽  
Critical Role ◽  
Co2 Reduction ◽  
First Principles Calculation ◽  
Bandgap Energy ◽  
Practical Implementation ◽  
Co2 Conversion ◽  
Defect Engineering

Pb-free double halide perovskites have drawn immense attention in the potential photocatalytic application, due to the regulatable bandgap energy and nontoxicity. Herein, we first present a study for CO2 conversion on Pb-free halide perovskite Cs2AgBiBr6 under state-of-the-art first-principles calculation with dispersion correction. Compared with the previous CsPbBr3, the cell parameter of Cs2AgBiBr6 underwent only a small decrease of 3.69%. By investigating the adsorption of CO, CO2, NO, NO2, and catalytic reduction of CO2, we found Cs2AgBiBr6 exhibits modest adsorption ability and unsatisfied potential determining step energy of 2.68 eV in catalysis. We adopted defect engineering (Cl doping, I doping and Br-vacancy) to regulate the adsorption and CO2 reduction behavior. It is found that CO2 molecule can be chemically and preferably adsorbed on Br-vacancy doped Cs2AgBiBr6 with a negative adsorption energy of −1.16 eV. Studying the CO2 reduction paths on pure and defect modified Cs2AgBiBr6, Br-vacancy is proved to play a critical role in decreasing the potential determining step energy to 1.25 eV. Finally, we probe into the electronic properties and demonstrate Br-vacancy will not obviously promote the process of catalysis deactivation, as there is no formation of deep-level electronic states acting as carrier recombination center. Our findings reveal the process of gas adsorption and CO2 reduction on novel Pb-free Cs2AgBiBr6, and propose a potential strategy to improve the efficiency of catalytic CO2 conversion towards practical implementation.

Water nanodomain for efficient photocatalytic CO2 reduction to CO

2021 ◽  
Author(s):  
Gang Chen ◽  
Xiuyan Cheng ◽  
Jianling Zhang ◽  
Qiang Wan ◽  
Ran Duan ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Evolution Rate ◽  
Co2 Conversion ◽  
Photocatalytic Co2 Conversion

Herein we propose the utilization of nanosized water domain for photocatalytic CO2 conversion, by which CO2 can be efficiently reduced to CO with CO evolution rate of 682 µmol g-1...

Enhancing CO2 photoreduction over ZIF-based reticular materials by morphology control of Au plasmonic nanoparticles

2022 ◽  
Author(s):  
Jorge Becerra ◽  
Vishnu Nair Gopalakrishnan ◽  
Toan-Anh Quach ◽  
Trong-On Do
Keyword(s):  
Band Structure ◽  
Energy Band ◽  
Co2 Reduction ◽  
Morphology Control ◽  
Energy Band Structure ◽  
Plasmonic Nanoparticles ◽  
Co2 Conversion ◽  
Zeolitic Imidazolate Frameworks ◽  
Co2 Photoreduction ◽  
Proper Energy

Zeolitic imidazolate frameworks (ZIFs) are promising photocatalysts for CO2 reduction due to their proper energy band structure and crystalline properties. However, CO2 conversion is still low due to the serious...

scholarly journals Materials and system design for direct electrochemical CO2 conversion in capture media

2021 ◽  
Author(s):  
Shuzhen Zhang ◽  
Celia Chen ◽  
Kangkang Li ◽  
Hai Yu ◽  
Fengwang Li
Keyword(s):  
System Design ◽  
Co2 Reduction ◽  
Value Added ◽  
Reduction Reaction ◽  
Co2 Conversion ◽  
Renewable Electricity ◽  
Electrochemical Co2 Reduction ◽  
Co2 Reduction Reaction

Electrochemical CO2 reduction reaction (eCO2RR) has been regarded as a promising means to store renewable electricity in the form of value-added chemicals or fuels. However, most of present eCO2RR studies...

scholarly journals Perovskites in the Energy Grid and CO2 Conversion: Current Context and Future Directions

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 95 ◽  
Author(s):  
Ahmad Tabish ◽  
Anish Mathai Varghese ◽  
Md A. Wahab ◽  
Georgios N. Karanikolos
Keyword(s):  
Energy Demand ◽  
Fossil Fuels ◽  
Co2 Reduction ◽  
Value Added ◽  
Clean Energy ◽  
High Catalytic Activity ◽  
Co2 Conversion ◽  
And Performance ◽  
Earth’S Climate ◽  
Conversion Technologies

CO2 emissions from the consumption of fossil fuels are continuously increasing, thus impacting Earth’s climate. In this context, intensive research efforts are being dedicated to develop materials that can effectively reduce CO2 levels in the atmosphere and convert CO2 into value-added chemicals and fuels, thus contributing to sustainable energy and meeting the increase in energy demand. The development of clean energy by conversion technologies is of high priority to circumvent these challenges. Among the various methods that include photoelectrochemical, high-temperature conversion, electrocatalytic, biocatalytic, and organocatalytic reactions, photocatalytic CO2 reduction has received great attention because of its potential to efficiently reduce the level of CO2 in the atmosphere by converting it into fuels and value-added chemicals. Among the reported CO2 conversion catalysts, perovskite oxides catalyze redox reactions and exhibit high catalytic activity, stability, long charge diffusion lengths, compositional flexibility, and tunable band gap and band edge. This review focuses on recent advances and future prospects in the design and performance of perovskites for CO2 conversion, particularly emphasizing on the structure of the catalysts, defect engineering and interface tuning at the nanoscale, and conversion technologies and rational approaches for enhancing CO2 transformation to value-added chemicals and chemical feedstocks.

scholarly journals Towards Higher Rate Electrochemical CO2 Conversion: From Liquid-Phase to Gas-Phase Systems

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 224 ◽  
Author(s):  
Jun Song ◽  
Hakhyeon Song ◽  
Beomil Kim ◽  
Jihun Oh
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Co2 Reduction ◽  
Value Added ◽  
Co2 Conversion ◽  
Co2 Solubility ◽  
Low Co2 ◽  
Phase Systems ◽  
Further Development ◽  
Value Added Products

Electrochemical CO2 conversion offers a promising route for value-added products such as formate, carbon monoxide, and hydrocarbons. As a result of the highly required overpotential for CO2 reduction, researchers have extensively studied the development of catalyst materials in a typical H-type cell, utilizing a dissolved CO2 reactant in the liquid phase. However, the low CO2 solubility in an aqueous solution has critically limited productivity, thereby hindering its practical application. In efforts to realize commercially available CO2 conversion, gas-phase reactor systems have recently attracted considerable attention. Although the achieved performance to date reflects a high feasibility, further development is still required in order for a well-established technology. Accordingly, this review aims to promote the further study of gas-phase systems for CO2 reduction, by generally examining some previous approaches from liquid-phase to gas-phase systems. Finally, we outline major challenges, with significant lessons for practical CO2 conversion systems.

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