scholarly journals CO2-Induced Fibrous Zn Catalyst Promotes Electrochemical Reduction of CO2 to CO

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 477
Author(s):  
Mengquan Guo ◽  
Xiangxiang Li ◽  
Yuxin Huang ◽  
Linfa Li ◽  
Jixiao Li ◽  
...  

The electrochemical reduction of CO2 is a promising strategy to achieve efficient conversion and utilization. In this paper, a series of Zn catalysts were prepared by electrodeposition in different atmospheric conditions (N2, CO2, H2, CO). A fibrous Zn catalyst (Zn-CO2) exhibits high electrochemical activity and stability. The Zn-CO2 catalyst shows 73.0% faradaic efficiency of CO at −1.2 V vs. RHE and the selectivity of CO almost did not change over 6 h in −1.2 V vs. RHE. The excellent selectivity and stability is attributed to the novel fibrous morphology, which increases the electrochemical active surface area. X-ray diffraction (XRD) results show that Zn-CO2 catalyst has a higher proportion of Zn (101) crystal planes, which is considered to be conducive to the production of CO. The search further demonstrates the importance of morphology control for the preparation of highly active and stable catalysts.

RSC Advances ◽  
2020 ◽  
Vol 10 (30) ◽  
pp. 17572-17581
Author(s):  
Nusrat Rashid ◽  
Mohsin Ahmad Bhat ◽  
U. K. Goutam ◽  
Pravin Popinand Ingole

Herein, we present fabrication of graphene oxide supported Cu/CuxO nano-electrodeposits which efficiently and selectively can electroreduce CO2 into ethylene with a faradaic efficiency of 34% and conversion rate of 194 mmol g−1 h−1 at −0.985 V vs. RHE.


Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1592
Author(s):  
Chunxiao Zhang ◽  
Shenglin Yan ◽  
Jing Lin ◽  
Qing Hu ◽  
Juhua Zhong ◽  
...  

Due to CO2 mass transfer limitation as well as the competition of hydrogen evolution reaction in electroreduction of CO2 in the aqueous electrolyte, Zn-based electrodes normally exhibit unsatisfying selectivity for CO production, especially at high potentials. In this work, we introduced a zinc myristate (Zn [CH3(CH2)12COO]2) hydrophobic layer on the surface of zinc foam electrode by an electrodeposition method. The obtained hydrophobic zinc foam electrode showed a high Faradaic efficiency (FE) of 91.8% for CO at −1.9 V (vs. saturated calomel electrode, SCE), which was a remarkable improvement over zinc foam (FECO = 81.87%) at the same potentials. The high roughness of the hydrophobic layer has greatly increased the active surface area and CO2 mass transfer performance by providing abundant gas-liquid-solid contacting area. This work shows adding a hydrophobic layer on the surface of the catalyst is an effective way to improve the electrochemical CO2 reduction performance.


2019 ◽  
Author(s):  
Emmanuel Abdul ◽  
Jason Pitts ◽  
Deepak Rajput ◽  
Shankar Rananavare

Gas sensors fabricated with antimony doped tin oxide (ATO) nanomaterials exhibit remarkable sensitivity for detecting oxidizing and reducing gases. This study highlights the enhanced selectivity and stability of the porous ATO nanomaterial electrode made for electrochemical reduction of CO2 in aqueous media. During electrochemical reduction, these electrodes prepared from compressed powders tend to crumble within a few hours in aqueous media. To overcome this electrode disintegration effect, we modified the surface of the doped tin-Oxide nanoparticles with Nafion and a dipodal silane (1,2-Bis(triethoxysilyl)ethane). The electrode characterization studies include Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS). Scanning electron microscopic investigation of electrode surface morphology and roughness before and after electrochemical CO2 reduction for derivatized and underivatized electrode revealed lower surface roughness for former than the latter.The derivatized electrodes allowed CO2 electrochemical reduction at low overpotentials and high current density without any electrode crumbling over more than 24 hours of continuous operation. Formate/formic acid and methanol were the major products of reduction at electrode potentials ranging from -0.4 to -1.0V vs. RHE in the CO2 saturated 0.1M KHCO3 electrolyte. Higher current density and Faradaic Efficiency of formic acid was observed when compared to planar tin electrode materials and tin oxide nanoparticles deposited on FTO glass.


2019 ◽  
Vol 3 (1) ◽  

A composite of copper and gold nanoparticles was deposited using arc plasma deposition on the conductive FTO substrate for the electrochemical reduction of CO2 . The use of arc plasma deposition system allows the nanoparticles to be implanted onto the substrate as opposed to the commonly used methods of vacuum deposition or electro deposition. This unique structure reduced the CO2 to produce formic acid with up to 60% faradaic efficiency. Copper and gold nanoparticles have never previously been reported to produce formic acid with such high efficiency, suggesting that the co-deposition technique of implanted nanoparticles can provide an interesting future avenue in the field of electrochemical reduction of CO2 . The surface analysis of the electrodes is presented here along with potential dependent faradaic efficiency of the electro catalysis.


Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2032 ◽  
Author(s):  
Beatriz Ávila-Bolívar ◽  
Leticia García-Cruz ◽  
Vicente Montiel ◽  
José Solla-Gullón

Herein, the electrochemical reduction of CO2 to formate on carbon-supported bismuth nanoparticles is reported. Carbon-supported Bi nanoparticles (about 10 nm in size) were synthesized using a simple, fast and scalable approach performed under room conditions. The so-prepared Bi electrocatalyst was characterized by different physicochemical techniques, including transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction and subsequently air-brushed on a carbon paper to prepare electrodes. These electrodes were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy and also by cyclic voltammetry. Finally, CO2 electroreduction electrolyses were performed at different electrode potentials for 3 h. At the optimal electrode potential (−1.6 V vs AgCl/Ag), the concentration of formate was about 77 mM with a faradaic efficiency of 93 ± 2.5%. A 100% faradaic efficiency was found at a lower potential (−1.5 V vs AgCl/Ag) with a formate concentration of about 55 mM. In terms of stability, we observed that after about 70 h (in 3 h electrolysis experiments at different potentials), the electrode deactivates due to the gradual loss of metal as shown by SEM/EDX analyses of the deactivated electrodes.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2354
Author(s):  
Katarzyna Bejtka ◽  
Nicolò B. D. Monti ◽  
Adriano Sacco ◽  
Micaela Castellino ◽  
Samuele Porro ◽  
...  

The electrocatalytic reduction of CO2 into useful fuels, exploiting rationally designed, inexpensive, active, and selective catalysts, produced through easy, quick, and scalable routes, represents a promising approach to face today’s climate challenges and energy crisis. This work presents a facile strategy for the preparation of doped SnO2 as an efficient electrocatalyst for the CO2 reduction reaction to formic acid and carbon monoxide. Zn or Ti doping was introduced into a mesoporous SnO2 matrix via wet impregnation and atomic layer deposition. It was found that doping of SnO2 generates an increased amount of oxygen vacancies, which are believed to contribute to the CO2 conversion efficiency, and among others, Zn wet impregnation resulted the most efficient process, as confirmed by X-ray photoelectron spectroscopy analysis. Electrochemical characterization and active surface area evaluation show an increase of availability of surface active sites. In particular, the introduction of Zn elemental doping results in enhanced performance for formic acid formation, in comparison to un-doped SnO2 and other doped SnO2 catalysts. At −0.99 V versus reversible hydrogen electrode, the total faradaic efficiency for CO2 conversion reaches 80%, while the partial current density is 10.3 mA cm−2. These represent a 10% and a threefold increases for faradaic efficiency and current density, respectively, with respect to the reference un-doped sample. The enhancement of these characteristics relates to the improved charge transfer and conductivity with respect to bare SnO2.


2020 ◽  
Vol 8 (30) ◽  
pp. 14966-14974 ◽  
Author(s):  
Jaecheol Choi ◽  
Jeonghun Kim ◽  
Pawel Wagner ◽  
Jongbeom Na ◽  
Gordon G. Wallace ◽  
...  

A highly ordered mesoporous carbon having a large surface area is utilized as a conductive substrate to immobilize iron porphyrin catalysts for electrochemical CO2 reduction, resulting in the selective conversion of aqueous CO2 into CO with 92.1% faradaic efficiency.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1172
Author(s):  
Magdalena Popczyk ◽  
Julian Kubisztal ◽  
Andrzej Szymon Swinarew ◽  
Zbigniew Waśkiewicz ◽  
Arkadiusz Stanula ◽  
...  

The paper presents research on evaluation of corrosion resistance of Ni-W alloy coatings subjected to heat treatment. The corrosion resistance was tested in 5% NaCl solution by the use of potentiodynamic polarization technique and electrochemical impedance spectroscopy. Characteristics of the Ni-W coatings after heat treatment were carried out using scanning electron microscopy, scanning Kelvin probe technique and X-ray diffraction. Suggested reasons for the improvement of properties of the heat treated Ni-W coating, obtained at the lowest current density value (125 mA∙cm−2), are the highest tungsten content (c.a. 25 at.%) as well as the smallest and the most homogeneous electrochemically active surface area.


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