CO2 reduction by single copper atom supported on g-C3N4 with asymmetrical active sites

2021 ◽  
Vol 540 ◽  
pp. 148293
Author(s):  
Sijia Fu ◽  
Xin Liu ◽  
Jingrun Ran ◽  
Yan Jiao ◽  
Shi-Zhang Qiao
Keyword(s):  
Copper Atom ◽  
Active Sites ◽  
Co2 Reduction

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 Facet-dependent active sites of a single Cu2O particle photocatalyst for CO2 reduction to methanol

Nature Energy ◽  
2019 ◽  
Vol 4 (11) ◽  
pp. 957-968 ◽  
Author(s):  
Yimin A. Wu ◽  
Ian McNulty ◽  
Cong Liu ◽  
Kah Chun Lau ◽  
Qi Liu ◽  
...  
Keyword(s):  
Active Sites ◽  
Co2 Reduction ◽  
Cu2o Particle

Atomic regulation of metal-organic framework derived carbon-based single-atom catalysts for electrochemical CO2 reduction reaction

2021 ◽  
Author(s):  
Danni Zhou ◽  
Xinyuan Li ◽  
Huishan Shang ◽  
Fengjuan Qin ◽  
Wenxing Chen
Keyword(s):  
Active Sites ◽  
Metal Organic Framework ◽  
Co2 Reduction ◽  
Carbon Dioxide Reduction ◽  
Reduction Reaction ◽  
Single Atom ◽  
Electrochemical Co2 Reduction ◽  
Metal Organic ◽  
Co2 Reduction Reaction ◽  
Organic Framework

Metal-organic framework (MOF) derived single-atom catalysts (SACs), featured unique active sites and adjustable topological structures, exhibit high electrocatalytic performance on carbon dioxide reduction reactions (CO2RR). By modulating elements and atomic...

Highly Efficient Proton-Assisted Photocatalytic CO2 Reduction over 3-Mercaptopropionic Acid-Capped CdS Quantum Dots

2021 ◽  
Author(s):  
Duc-Trung Nguyen ◽  
Anis Chouat ◽  
Trong-On Do
Keyword(s):  
Quantum Dots ◽  
Active Sites ◽  
Co2 Reduction ◽  
Cds Quantum Dots ◽  
Capping Agents ◽  
Mercaptopropionic Acid ◽  
Highly Efficient

Herein, we demonstrate that 3-mercaptopropionate capping agents on CdS quantum dots' surface could serve as proton shutters and localize protons near the active sites toward an efficient photocatalytic CO2 reduction....

scholarly journals Size Dependent CO2 Reduction Activity of Ag Nanoparticle Electrocatalysts

2021 ◽  
Author(s):  
Xingyi Deng ◽  
Dominic Alfonso ◽  
Thuy-Duong Nguyen-Phan ◽  
Douglas Kauffman
Keyword(s):  
Active Sites ◽  
Density Functional ◽  
Particle Diameter ◽  
Small Diameter ◽  
Co2 Reduction ◽  
High Population ◽  
Structure Property ◽  
Size Dependent ◽  
Catalyst Utilization ◽  
Ag Catalysts

Abstract Coinage metals (Au, Cu and Ag) are state-of-the-art electrocatalysts for the CO2 reduction reaction (CO2RR). Size-dependent CO2RR activity of Au and Cu has been studied, and increased H2 evolution reaction (HER) activity is expected for small catalyst particles with high population of undercoordinated corner sites. A similar consensus is still lacking for Ag catalysts because the ligands and stabilizers typically used to control particle synthesis can block specific active sites and mask inherent structure-property trends. This knowledge gap is problematic because increased performance and catalyst utilization are still needed to improve economic viability. We combined density functional theory, microkinetic modeling, and experiment to demonstrate a strong size-dependence for pristine Ag particles in the sub-10 nm range. Small diameter particles with a high population of Ag edge sites were predicted to favor HER, whereas CO2RR selectivity increased towards that of bulk Ag for larger diameter particles as the population of Ag(100) surface sites grew. Experimental results validated these predictions and we identified an optimal particle diameter of 8-10 nm that balanced selectivity and activity. Particles below this diameter suffered from poor selectivity, while larger particles demonstrated bulk-like activity and reduced catalyst utilization. These results demonstrate the size-dependent CO2RR activity of pristine Ag catalysts and will help guide future development efforts.

First-Principles DFT Insights into the Mechanisms of CO2 Reduction to CO on Fe (100)-Ni Bimetals

2021 ◽  
Author(s):  
Caroline Kwawu ◽  
Albert Aniagyei ◽  
Destiny Konadu ◽  
Elliot Menkah ◽  
Richard Tia
Keyword(s):  
Carbon Monoxide ◽  
Binding Site ◽  
Active Sites ◽  
Density Functional ◽  
Co2 Reduction ◽  
Density Functional Theory Calculations ◽  
Hydrocarbon Fuel ◽  
Generalized Gradient ◽  
Efficient Catalyst ◽  
Stepped Surface

Abstract Iron and nickel are known active sites in the enzyme carbon monoxide dehydrogenases (CODH) which catalyzes CO2 to CO reversibly. The presence of nickel impurities in the earth abundant iron surface could provide a more efficient catalyst for CO2 degradation into CO, which is a feedstock for hydrocarbon fuel production. In the present study, we have employed spin-polarized dispersion-corrected density functional theory calculations within the generalized gradient approximation to elucidate the active sites on Fe (100)-Ni bimetals. We sort to ascertain the mechanism of CO2 dissociation to carbon monoxide on Ni deposited and alloyed surfaces at 0.25, 0.50 and 1 monolayer (ML) impurity concentrations. CO2 and (CO + O) bind exothermically i.e., -0.87 eV and − 1.51 eV respectively to the bare Fe (100) surface with a decomposition barrier of 0.53 eV. The presence of nickel generally lowers the amount of charge transferred to CO2 moiety. Generally, the binding strengths of CO2 were reduced on the modified surfaces and the extent of its activation was lowered. The barriers for CO2 dissociation increased mainly upon introduction of Ni impurities which is undesired. However, the 0.5 ML deposited (FeNi0.5(A)) surface is promising for CO2 decomposition, providing a lower energy barrier (of 0.32 eV) than the pristine Fe (100) surface. This active 1-dimensional defective FeNi0.5(A) surface provides a stepped surface and Ni-Ni bridge binding site for CO2 on Fe (100). Ni-Ni bridge site on Fe (100) is more effective for both CO2 binding or sequestration and dissociation compared to the stepped surface providing the Fe-Ni bridge binding site.

In Situ-Grown Island-Shaped Hollow Graphene on TaON with Spatially Separated Active Sites Achieving Enhanced Visible-Light CO2 Reduction

ACS Catalysis ◽  
2020 ◽  
Vol 10 (24) ◽  
pp. 15083-15091
Author(s):  
Lang Pei ◽  
Yongjun Yuan ◽  
Wangfeng Bai ◽  
Taozhu Li ◽  
Heng Zhu ◽  
...  
Keyword(s):  
Visible Light ◽  
Active Sites ◽  
Co2 Reduction
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