Substituents and Cocatalyst Effect on the Catalytic Response and Overpotential of Re(I) Catalysts for CO2 Reduction
Mahsasadat Boraghi
;
Travis A. White
;
Shabnam Pordel
, et al.
ACS Appl. Energy Mater.,2021,4(12):13725-13734.
DOI:
10.1021/acsaem.1c02462
More
Abstract: To design an efficient electrocatalyst for CO2 reduction, a comprehensive understanding of the catalytic architecture and the reaction mechanism is required. Herein, we synthesized and analyzed a series of fac-[Re(bpy-X) (CO)3Cl] (abbreviated as ReI(bpy-X); bpy-X = 4,4′-disubstituted-2,2′-bipyridine; X = tBu, CH3, mesityl, H, phenyl, and methyl ester) catalysts for electrocatalytic CO2 reduction with and without adding the cocatalyst [Zn(cyclam)]2+ (cyclam = 1,4,6,11-tetraazacyclotetradecane). Both computational and experimental results show that in the experiments bearing the [Zn(cyclam)]2+ cocatalyst, the Re(I) catalysts require less energy input to reduce the CO2, indicating that the CO2-to-CO conversion occurs at a lower overpotential. Interestingly, in the Re(I) electrocatalyst bearing a strong electron-withdrawing group (methyl ester), [Zn(cyclam)]2+ does not improve the CO2 reduction activity. These results emphasize the importance of how the electronic distribution throughout the molecular architecture can enhance or suppress the nucleophilicity of ReI(bpy-X) electrocatalysts, even in the presence of a cocatalyst.
Keywords:
rhenium electrocatalyst ;
zinc cocatalyst ;
CO2 reduction ;
substituent effect ;
DFT calculations
Purchased from AmBeed:
295-37-4
 Catalysts for CO2 Reduction.png)
Mechanistic insight into electrocatalytic CO2 reduction using Lewis acid-base pairs
Mahsasadat Boraghi
;
Travis A. White
;
Inorg. Chim. Acta,2021,526,120528.
DOI:
10.1016/j.ica.2021.120528
More
Abstract: In this study, fac-[Re(bpy)(CO)3Cl] (bpy = 2,2′-bipyridine) is used as a Lewis base catalyst and [Zn(cyclam)]2+(cyclam = 1,4,8,11-tetraazacyclotetradecane) is used as a Lewis acid co-catalyst. The thermodynamic effect of the [Zn(cyclam)]2+ on the redox activity of the ReI(bpy) catalyst for CO2 reduction has been investigated experimentally using cyclic voltammetry and computationally using density functional theory (DFT). Both experimental and computational results reveal that [Zn(cyclam)]2+ facilitates the Cl− ion dissociation by forming an inner-sphere interaction. As a result, the addition of [Zn(cyclam)]2+ shifts the ReI(bpy) first reduction to less negative potential, enabling the catalyst to be activated with less energy input. Moreover, we are proposing that [Zn(cyclam)]2+ decreases the CO2 reduction overpotential by the ReI(bpy) complex by stabilizing the CO2 binding energy.
Keywords:
Electrocatalytic CO2 reduction ;
Rhenium bipyridine ;
Zinc cyclam ;
Cyclic voltammetry ;
DFT
Purchased from AmBeed:
295-37-4
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
120K+ Compounds
Competitive Price
1-2 Day Shipping
