Tuning Sn-Cu Catalysis for Electrochemical Reduction of CO2 on Partially Reduced Oxides SnOx-CuOx-Modified Cu Electrodes

Copper-based bimetallic catalysts have been recently showing promising performance for the selective electrochemical reduction of CO2. In this work, we successfully fabricated the partially reduced oxides SnOx, CuOxmodified Cu foam electrode (A-Cu/SnO2) through an electrodeposition-annealing-electroreduction approach. Notably, in comparison with the control electrode (Cu/SnO2) without undergoing annealing step, A-Cu/SnO2 exhibits a significant enhancement in terms of CO2 reduction activity and CO selectivity. By investigating the effect of the amount of the electrodeposited SnO2, it is found that A-Cu/SnO2 electrodes present the characteristic Sn-Cu synergistic catalysis with a feature of dominant CO formation (CO faradaic efficiency, 70~75%), the least HCOOH formation (HCOOH faradaic efficiency, <5%) and the remarkable inhibition of hydrogen evolution reaction. In contrast, Cu/SnO2 electrodes exhibit a SnO2 coverage-dependent catalysis—a shift from CO selectivity to HCOOH selectivity with the increasing deposited SnO2 on Cu foam. The different catalytic performance between Cu/SnO2 and A-Cu/SnO2 might be attributed to the different content of Cu atoms in SnO2 layer, which may affect the density of Cu-Sn interface on the surface. Our work provides a facile annealing-electroreduction strategy to modify the surface composition for understanding the metal effect towards CO2 reduction activity and selectivity for bimetallic Cu-based electrocatalysts.

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Mo–Bi Bimetallic Chalcogenide Nanoparticles Supported on CNTs for the Efficient Electrochemical Reduction of CO2 to Methanol

Coatings ◽

10.3390/coatings10121142 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1142

Author(s):

Chen Chi ◽

Donghong Duan ◽

Zhonglin Zhang ◽

Guoqiang Wei ◽

Yu Li ◽

...

Keyword(s):

Electrochemical Reduction ◽

Average Particle Size ◽

Reference Electrode ◽

Catalytic Performance ◽

Industrial Applications ◽

Saturated Calomel Reference Electrode ◽

Average Particle ◽

One Pot ◽

Faradaic Efficiency ◽

Reduction Of Co2

The electrochemical reduction of CO2 to methanol is a promising strategy, which currently suffers from the poor catalytic activity, selectivity, and stability of the electrode. Here, we report a simple one-pot hydrothermal strategy to fabricate Mo–Bi BMC@CNT nanocomposites, in which Mo–Bi bimetallic chalcogenide nanoparticles were in-situ decorated on carbon nanotubes. The Mo–Bi BMC nanoparticles with an average particle size of 12 nm were uniformly supported on the surface of CNTs without aggregation into larger clusters. The Mo–Bi BMC@CNT nanocomposites exhibited a relatively good catalytic performance for the electrochemical reduction of CO2 to methanol in a 60 wt.% 1-ethyl-3-methylimidazolium tetrafluoroborate aqueous electrolyte. Among them, the Mo–Bi BMC@CNT-15% nanocomposite showed the highest Faradaic efficiency of 81% for methanol at −0.3 V vs. a saturated calomel reference electrode (SCE) and a stable current density is 5.6 mA cm−2 after a run time of 12 h. The excellent catalytic properties are likely attributed to its nanostructure and fast electron transfer. These derive from the synergistic effect of Mo–Bi and the high conductivity of CNTs. This work opens a way to provide an efficient catalytic system for the electroreduction of CO2 to methanol in industrial applications.

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Copper–Silver Bimetallic Nanowire Arrays for Electrochemical Reduction of Carbon Dioxide

Nanomaterials ◽

10.3390/nano9020173 ◽

2019 ◽

Vol 9 (2) ◽

pp. 173 ◽

Cited By ~ 9

Author(s):

Yuanxing Wang ◽

Cailing Niu ◽

Yachuan Zhu

Keyword(s):

Carbon Dioxide ◽

Electrochemical Reduction ◽

Co2 Reduction ◽

Ambient Air ◽

Catalytic Performance ◽

Nanowire Arrays ◽

Liquid Fuels ◽

Galvanic Replacement ◽

Cu Nanowires ◽

Reduction Of Co2

The electrochemical conversion of carbon dioxide (CO2) into gaseous or liquid fuels has the potential to store renewable energies and reduce carbon emissions. Here, we report a three-step synthesis using Cu–Ag bimetallic nanowire arrays as catalysts for electrochemical reduction of CO2. CuO/Cu2O nanowires were first grown by thermal oxidation of copper mesh in ambient air and then reduced by annealing in the presence of hydrogen to form Cu nanowires. Cu–Ag bimetallic nanowires were then produced via galvanic replacement between Cu nanowires and the Ag+ precursor. The Cu–Ag nanowires showed enhanced catalytic performance over Cu nanowires for electrochemical reduction of CO2, which could be ascribed to the incorporation of Ag into Cu nanowires leading to suppression of hydrogen evolution. Our work provides a method for tuning the selectivity of copper nanocatalysts for CO2 reduction by controlling their composition.

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Efficient Electrochemical Reduction of CO2 to CO in Ionic Liquid/Propylene Carbonate Electrolyte on Ag Electrode

Catalysts ◽

10.3390/catal10101102 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1102

Author(s):

Fengyang Ju ◽

Jinjin Zhang ◽

Weiwei Lu

Keyword(s):

Ionic Liquids ◽

Electrochemical Reduction ◽

Propylene Carbonate ◽

Value Added ◽

Catalytic Performance ◽

Co2 Conversion ◽

Imidazolium Cation ◽

Faradaic Efficiency ◽

Ag Electrode ◽

Reduction Of Co2

The electrochemical reduction of CO2 is a promising way to recycle it to produce value-added chemicals and fuels. However, the requirement of high overpotential and the low solubility of CO2 in water severely limit their efficient conversion. To overcome these problems, in this work, a new type of electrolyte solution constituted by ionic liquids and propylene carbonate was used as the cathodic solution, to study the conversion of CO2 on an Ag electrode. The linear sweep voltammetry (LSV), Tafel characterization and electrochemical impedance spectroscopy (EIS) were used to study the catalytic effect and the mechanism of ionic liquids in electrochemical reduction of CO2. The LSV and Tafel characterization indicated that the chain length of 1-alkyl-3-methyl imidazolium cation had strong influences on the catalytic performance for CO2 conversion. The EIS analysis showed that the imidazolium cation that absorbed on the Ag electrode surface could stabilize the anion radical (CO2•−), leading to the enhanced efficiency of CO2 conversion. At last, the catalytic performance was also evaluated, and the results showed that Faradaic efficiency for CO as high as 98.5% and current density of 8.2 mA/cm2 could be achieved at −1.9 V (vs. Fc/Fc+).

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Graphene Supported Tungsten Carbide as Catalyst for Electrochemical Reduction of CO2

10.26434/chemrxiv.8280986 ◽

2019 ◽

Author(s):

Sahithi Ananthaneni ◽

Rees Rankin

Keyword(s):

Tungsten Carbide ◽

Electrochemical Reduction ◽

Low Cost ◽

Co2 Reduction ◽

Platinum Group Metal ◽

Reduction Reaction ◽

Metal Carbides ◽

Depth Study ◽

Reduction Of Co2 ◽

Co2 Reduction Reaction

<div>Electrochemical reduction of CO2 to useful chemical and fuels in an energy efficient way is currently an expensive and inefficient process. Recently, low-cost transition metal-carbides (TMCs) are proven to exhibit similar electronic structure similarities to Platinum-Group-Metal (PGM) catalysts and hence can be good substitutes for some important reduction reactions. In this work, we test graphenesupported WC (Tungsten Carbide) nanocluster as an electrocatalyst for the CO2 reduction reaction. Specifically, we perform DFT studies to understand various possible reaction mechanisms and determine the lowest thermodynamic energy landscape of CO2 reduction to various products such as CO, HCOOH, CH3OH, and CH4. This in-depth study of reaction energetics could lead to improvements and develop more efficient electrocatalysts for CO2 reduction.<br></div>

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CuZnAl-Oxide Nanopyramidal Mesoporous Materials for the Electrocatalytic CO2 Reduction to Syngas: Tuning of H2/CO Ratio

Nanomaterials ◽

10.3390/nano11113052 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3052

Author(s):

Hilmar Guzmán ◽

Daniela Roldán ◽

Adriano Sacco ◽

Micaela Castellino ◽

Marco Fontana ◽

...

Keyword(s):

Noble Metals ◽

Co2 Reduction ◽

Reduction Process ◽

Mesoporous Structure ◽

Catalytic Performance ◽

H2 Production ◽

Ambient Conditions ◽

Transfer Resistance ◽

Faradaic Efficiency ◽

Co2 Electroreduction

Inspired by the knowledge of the thermocatalytic CO2 reduction process, novel nanocrystalline CuZnAl-oxide based catalysts with pyramidal mesoporous structures are here proposed for the CO2 electrochemical reduction under ambient conditions. The XPS analyses revealed that the co-presence of ZnO and Al2O3 into the Cu-based catalyst stabilize the CuO crystalline structure and introduce basic sites on the ternary as-synthesized catalyst. In contrast, the as-prepared CuZn- and Cu-based materials contain a higher amount of superficial Cu0 and Cu1+ species. The CuZnAl-catalyst exhibited enhanced catalytic performance for the CO and H2 production, reaching a Faradaic efficiency (FE) towards syngas of almost 95% at −0.89 V vs. RHE and a remarkable current density of up to 90 mA cm−2 for the CO2 reduction at −2.4 V vs. RHE. The physico-chemical characterizations confirmed that the pyramidal mesoporous structure of this material, which is constituted by a high pore volume and small CuO crystals, plays a fundamental role in its low diffusional mass-transfer resistance. The CO-productivity on the CuZnAl-catalyst increased at more negative applied potentials, leading to the production of syngas with a tunable H2/CO ratio (from 2 to 7), depending on the applied potential. These results pave the way to substitute state-of-the-art noble metals (e.g., Ag, Au) with this abundant and cost-effective catalyst to produce syngas. Moreover, the post-reaction analyses demonstrated the stabilization of Cu2O species, avoiding its complete reduction to Cu0 under the CO2 electroreduction conditions.

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Electrochemical reduction of CO2 to ethylene on Cu/CuxO-GO composites in aqueous solution

RSC Advances ◽

10.1039/d0ra02754e ◽

2020 ◽

Vol 10 (30) ◽

pp. 17572-17581

Author(s):

Nusrat Rashid ◽

Mohsin Ahmad Bhat ◽

U. K. Goutam ◽

Pravin Popinand Ingole

Keyword(s):

Aqueous Solution ◽

Graphene Oxide ◽

Electrochemical Reduction ◽

Conversion Rate ◽

Faradaic Efficiency ◽

Reduction Of Co2

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.

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Graphene Supported Tungsten Carbide as Catalyst for Electrochemical Reduction of CO2

Catalysts ◽

10.3390/catal9070604 ◽

2019 ◽

Vol 9 (7) ◽

pp. 604

Author(s):

Sahithi Ananthaneni ◽

Zachery Smith ◽

Rees B. Rankin

Keyword(s):

Tungsten Carbide ◽

Electrochemical Reduction ◽

Density Functional ◽

Low Cost ◽

Co2 Reduction ◽

Platinum Group Metal ◽

Reduction Reaction ◽

Depth Study ◽

Reduction Of Co2 ◽

Co2 Reduction Reaction

Electrochemical reduction of CO2 to useful chemical and fuels in an energy efficient way is currently an expensive and inefficient process. Recently, low-cost transition metal-carbides (TMCs) have been proven to exhibit similar electronic structure similarities to Platinum-Group-Metal (PGM) catalysts and hence, can be good substitutes for some important reduction reactions. In this work, we test graphene-supported WC (Tungsten Carbide) nanoclusters as an electrocatalyst for the CO2 reduction reaction. Specifically, we perform density functional theory (DFT) studies to understand various possible reaction mechanisms and determine the lowest thermodynamic energy landscape of CO2 reduction to various products, such as CO, HCOOH, CH3OH, and CH4. This in-depth study of reaction energetics could lead to improvements and development of more efficient electrocatalysts for CO2 reduction.

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Low-Overpotential Electrochemical Reduction of CO2 to Formic Acid on Surface-Modified Doped Tin Oxide Pellets

10.1149/osf.io/2u8ba ◽

2019 ◽

Author(s):

Emmanuel Abdul ◽

Jason Pitts ◽

Deepak Rajput ◽

Shankar Rananavare

Keyword(s):

Formic Acid ◽

Electrochemical Reduction ◽

Current Density ◽

Tin Oxide ◽

Aqueous Media ◽

Oxide Nanoparticles ◽

Faradaic Efficiency ◽

Electrode Potentials ◽

Tin Oxide Nanoparticles ◽

Reduction Of Co2

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.

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Arc Plasma Deposited Copper and Gold Nanoparticles on FTO Substrate for Electrochemical Reduction of CO2

Advances in Nanoscience and Nanotechnology ◽

10.33140/ann.03.01.03 ◽

2019 ◽

Vol 3 (1) ◽

Keyword(s):

Gold Nanoparticles ◽

Formic Acid ◽

Electrochemical Reduction ◽

High Efficiency ◽

Plasma Deposition ◽

Arc Plasma ◽

Faradaic Efficiency ◽

Electro Deposition ◽

Electro Catalysis ◽

Reduction Of Co2

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.

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Photoelectrochemical Reduction of CO2 to Syngas by Reduced Ag Catalysts on Si Photocathodes

Applied Sciences ◽

10.3390/app10103487 ◽

2020 ◽

Vol 10 (10) ◽

pp. 3487 ◽

Cited By ~ 1

Author(s):

Changyeon Kim ◽

Seokhoon Choi ◽

Min-Ju Choi ◽

Sol A Lee ◽

Sang Hyun Ahn ◽

...

Keyword(s):

Catalytic Activity ◽

Active Sites ◽

Co2 Reduction ◽

Reduction Reaction ◽

Hydrogen Electrode ◽

Faradaic Efficiency ◽

Onset Potential ◽

Reduction Of Co2 ◽

Co2 Reduction Reaction ◽

Ag Catalysts

The photoelectrochemical reduction of CO2 to syngas that is used for many practical applications has been emerging as a promising technique to relieve the increase of CO2 in the atmosphere. Si has been considered to be one of the most promising materials for photoelectrodes, but the integration of electrocatalysts is essential for the photoelectrochemical reduction of CO2 using Si. We report an enhancement of catalytic activity for CO2 reduction reaction by Ag catalysts of tuned morphology, active sites, and electronic structure through reducing anodic treatment. Our proposed photocathode structure, a SiO2 patterned p-Si photocathode with these reduced Ag catalysts, that was fabricated using electron-beam deposition and electrodeposition methods, provides a low onset-potential of −0.16 V vs. the reversible hydrogen electrode (RHE), a large saturated photocurrent density of −9 mA/cm2 at −1.23 V vs. RHE, and faradaic efficiency for CO of 47% at −0.6 V vs. RHE. This photocathode can produce syngas in the ratio from 1:1 to 1:3, which is an appropriate proportion for practical application. This work presents a new approach for designing photocathodes with a balanced catalytic activity and light absorption to improve the photoelectrochemical application for not only CO2 reduction reaction, but also water splitting or N2 reduction reaction.

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