Electroreduction Of Carbon Monoxide Research Articles

Establishing Non‐Stoichiometric Ti4O7 Assisted Asymmetrical C−C Coupling for Highly Energy‐Efficient Electroreduction of Carbon Monoxide

AbstractExploring an appropriate support material for Cu‐based electrocatalyst is conducive for stably producing multi‐carbon chemicals from electroreduction of carbon monoxide. However, the insufficient metal‐support adaptability and low conductivity of the support would hinder the C−C coupling capacity and energy efficiency. Herein, non‐stoichiometric Ti4O7 was incorporated into Cu electrocatalysts (Cu−Ti4O7), and served as a highly conductive and stable support for highly energy‐efficient electrochemical conversion of CO. The abundant oxygen vacancies originated from ordered lattice defects in Ti4O7 facilitate the water dissociation and the CO adsorption to accelerate the hydrogenation to *COH. The highly adaptable metal‐support interface of Cu−Ti4O7 enables a direct asymmetrical C−C coupling between *CO on Cu and *COH on Ti4O7, which significantly lowers the reaction energy barrier for C2+ products formation. Additionally, the excellent electroconductivity of Ti4O7 benefits the reaction charge transfer through robust Cu/Ti4O7 interface for minimizing the energy loss. Thus, the optimized 20Cu−Ti4O7 catalyst exhibits an impressive selectivity of 96.4 % and ultrahigh energy efficiency of 45.1 % for multi‐carbon products, along with a remarkable partial current density of 432.6 mA cm−2. Our study underscores a novel C−C coupling strategy between Cu and the support material, advancing the development of Cu‐supported catalysts for highly efficient electroreduction of carbon monoxide.

Bioinspired molecule-functionalized Cu with high CO adsorption for efficient CO electroreduction to acetate.

Electrochemical reduction of carbon dioxide (CO2) or carbon monoxide (CO) to valuable multi-carbon (C2+) products like acetate is a promising approach for a sustainable energy economy. However, it is still challenging to achieve high activity and selectivity for acetate production, especially in neutral electrolytes. Herein, a bioinspired hemin/Cu hybrid catalyst was developed to enhance the surface *CO coverage for highly efficient electroreduction of CO to acetate fuels. The hemin/Cu electrocatalyst exhibits a remarkable faradaic efficiency of 45.2% for CO-to-acetate electroreduction and a high acetate partial current density of 152.3 mA cm-2. Furthermore, the developed hybrid catalyst can operate stably at 200 mA cm-2 for 14.6 hours, producing concentrated acetate aqueous solutions (0.235 M, 2.1 wt%). The results of in situ Raman spectroscopy and theoretical calculations proved that the Fe-N4 structure of hemin could enhance the CO adsorption and enrich the local concentration of CO, thereby improving C-C coupling for acetate production. In addition, compared to the unmodified Cu catalysts, the Cu catalysts functionalized with cobalt phthalocyanine with a Co-N4 structure also exhibit improved acetate performance, proving the universality of this bioinspired molecule-enhanced strategy. This work paves a new way to designing bioinspired electrolysis systems for producing specific C2+ products from CO2 or CO electroreduction.

Progress in the application of Cu-based catalysts in the electroreduction of CO2 to produce Cxs products

Since the industrial revolution, human dependence on fossil fuels has resulted in increasingly severe atmospheric carbon dioxide (CO2) emissions. Electrocatalytic CO2 RR has attracted much attention because of its many advantages, such as mild reaction conditions, controllable reaction rate, low cost and scalable electrolyzer.[7] More importantly, electrocatalytic CO2 RR can control the selective generation of target products by rationally adjusting the reaction potential, electrolyte and catalyst species. However, the CO2 molecular structure is stable, and obtaining the key CO2 -based anionic intermediate CO2– from activated CO2 molecules requires overcoming a huge energy barrier. Copper (Cu) catalysts are the only monometallic catalysts to date that can form two-carbon (C2) products, which establishes their special position in the field. However, the poor selectivity of Cu for a particular product has led to a wide distribution of reduction products, covering the range from carbon monoxide (CO), a reduction product at 2e-, to ethanol (C H25 OH), a reduction product at 12e-. Meanwhile, Cu catalysts are generally less stable, which can seriously affect their commercialization. Currently, in order to obtain highly selective C2+ products (mainly ethylene and ethanol), [16]this article reviews the various methods developed by different scholars in China and abroad to modify Cu catalysts. Finally, this article suggests ways to improve the performance of Cu-based catalysts to enhance the Faraday efficiency of the C2 product from the electroreduction of C02 and gives an outlook on the future direction of Cu-based catalysts.[19]

Correction: Local reaction environment for selective electroreduction of carbon monoxide

Correction for ‘Local reaction environment for selective electroreduction of carbon monoxide’ by Ming Ma et al., Energy Environ. Sci., 2022, https://doi.org/10.1039/d1ee03838a.

Pulsed Electrochemical Carbon Monoxide Reduction on Oxide-Derived Copper Catalyst.

Efficient electroreduction of carbon dioxide has been a widely pursued goal as a sustainable method to produce value-added chemicals while mitigating greenhouse gas emissions. Processes have been demonstrated for the electroreduction of CO2 to CO at nearly 100 % faradaic efficiency, and as a consequence, there has been growing interest in the further electroreduction of carbon monoxide. Oxide-derived copper catalysts have promising performance for the reduction of CO to hydrocarbons but have still been unable to achieve high selectivity to individual products. A pulsed-bias technique is one strategy for tuning electrochemical selectivity without changing the catalyst. Herein a pulsed-bias electroreduction of CO was investigated on oxide-derived copper catalyst. Increased selectivity for single-carbon products (i.e., formate and methane) was achieved for higher pulse frequencies (<1 s pulse times), as well as an increase in the fraction of charge directed to CO reduction rather than hydrogen evolution.

Nanoporous Metal–Organic Framework-Based Ellipsoidal Nanoparticles for the Catalytic Electroreduction of CO2

Electroreduction of carbon dioxide (CO2) to carbon monoxide (CO) is a promising strategy to reduce the superfluous CO2 in the atmosphere while simultaneously generating renewable fuel and crucial r...

Single‐Atom Iron‐Nitrogen Catalytic Site with Graphitic Nitrogen for Efficient Electroreduction of CO2

AbstractElectrochemical reduction of CO2 to carbon monoxide (CO) and other useful fuels/chemicals offers a green and promising technical solution for alleviating greenhouse effect and creating economic benefits. Herein, we developed a single‐atom Fe dispersed on N‐doped carbons nanosheet (Fe−SA/NCS−X) for CO2 electroreduction by direct pyrolysis of hemin‐doped polyaniline fabricated by in‐situ chemical polymerization. The Fe‐SA/NCS‐700 achieved a Faraday efficiency of CO up to 87 % at −0.45 V vs. RHE, a low onset overpotential of 105 mV and remarkable durability with the current density being maintained for 10 h constant electrocatalysis, which were comparable to the latest reported single‐atom catalysts. The Tafel slope of Fe‐SA/NCS‐700 was measured to be about 67 mV/dec, close to theoretical value of 59 mV/dec, which indicated a rapid pre‐equilibrating one‐electron transfer followed by a rate‐determining reaction step. DFT calculations revealed that the graphitic N species can synergistically improve the catalytic activities of Fe‐N4 sites of Fe‐SA/NCS−X by significantly lowering the free energy barriers of *COOH intermediate formation, thus promoting CO2 electroreduction to CO.

Frontispiz: Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide

Frontispiz: Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide

Frontispiece: Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide

Frontispiece: Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide

Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide.

Conversion of carbon monoxide to high value-added ethylene with high selectivity by traditional syngas conversion process is challenging because of the limitation of Anderson-Schulz-Flory distribution. Herein we report a direct electrocatalytic process for highly selective ethylene production from CO reduction with water over Cu catalysts at room temperature and ambient pressure. An unprecedented 52.7 % Faradaic efficiency of ethylene formation is achieved through optimization of cathode structure to facilitate CO diffusion at the surface of the electrode and Cu catalysts to enhance the C-C bond coupling. The highly selective ethylene production is almost without other carbon-based byproducts (e.g. C1 -C4 hydrocarbons and CO2 ) and avoids the drawbacks of the traditional Fischer-Tropsch process that always delivers undesired products. This study provides a new and promising strategy for highly selective production of ethylene from the abundant industrial CO.

Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide

AbstractConversion of carbon monoxide to high value‐added ethylene with high selectivity by traditional syngas conversion process is challenging because of the limitation of Anderson‐Schulz–Flory distribution. Herein we report a direct electrocatalytic process for highly selective ethylene production from CO reduction with water over Cu catalysts at room temperature and ambient pressure. An unprecedented 52.7 % Faradaic efficiency of ethylene formation is achieved through optimization of cathode structure to facilitate CO diffusion at the surface of the electrode and Cu catalysts to enhance the C−C bond coupling. The highly selective ethylene production is almost without other carbon‐based byproducts (e.g. C1–C4 hydrocarbons and CO2) and avoids the drawbacks of the traditional Fischer–Tropsch process that always delivers undesired products. This study provides a new and promising strategy for highly selective production of ethylene from the abundant industrial CO.

High Rate, Selective, and Stable Electroreduction of CO2 to CO in Basic and Neutral Media

The electroreduction of carbon dioxide (CO2) to chemicals such as carbon monoxide (CO) shows great potential for renewable fuel and chemical production. Significant progress in individual performance metrics such as reaction rate, selectivity, and stability has been achieved, yet the simultaneous achievement of each of these key metrics within a single system, and in a wide range of operating conditions, has yet to be demonstrated. Here we report a composite multilayered porous electrode consisting of a polytetrafluoroethylene gas distribution layer, a conformal Ag catalyst, and a carbon current distributor. Separating the gas and current distribution functions provides endurance, and further reconstructing the catalyst to carbonate-derived Ag provides flexibility in terms of electrolyte. The resulting electrodes reduce CO2 to CO with a Faradaic efficiency over 90% at current densities above 150 mA/cm2, in both neutral and alkaline media for over 100 h of operation. This represents an important step towar...

Electrode Characterization in a Flowing Electrolyte Reactor for the Electrochemical Reduction of CO2 to CO

The development of an energy efficient carbon dioxide (CO2) electroreduction process could simultaneously curb anthropogenic CO2 emissions and provide a sustainable pathway for the generation of chemicals and fuels. Pursuant to this goal, significant efforts have been devoted to developing novel electrocatalysts that enable selective CO2 reduction, at low overpotentials, to a range of valuable products. Of particular interest is carbon monoxide (CO), a key component of synthesis gas, along with hydrogen, which, through Fischer-Tropsch processing, can be used to generate a range of liquid hydrocarbons. While many metals are capable of forming CO as the primary CO2 reduction product, gold may offer the best combination of activity, selectivity, and stability1,2. In contrast to the concerted efforts on catalyst development, fewer studies3–5 have sought to characterize electrode performance within operating electrolyzers, particularly under operating conditions and in cell configurations that more closely align with practical application. To this end, we seek to develop high performance electrodes for the reduction of CO2 to CO and to quantify performance-limiting factors of those electrodes in a gas-liquid electrochemical flow cell. Drawing from advanced polymer electrolyte fuel cell and electrolyzer designs, we have developed a flowing electrolyte electrochemical reactor with gas phase reactant delivery and a reference electrode directly between the anode and cathode. Serving as an analytical platform, the configuration enables in-situ investigation of electrode performance via a combination of polarization and electrochemical impedance spectroscopy. Specifically, we aim to quantify and mitigate resistive losses (e.g., kinetic, ohmic, mass transport) as a function of electrode preparation, cell configuration, and operating conditions. Developing a better understanding of the electrode performance within an operating cell can inform future catalyst / electrode development campaigns for a range of CO2 reduction systems. 1. Hori, Y., Wakebe, H., Tsukamoto, T. & Koga, O. Electrocatalytic process of CO selectivity in electrochemical reduction of CO2 at metal electrodes in aqueous media. Electrochimica Acta 39, 1833–1839 (1994). 2. Salih, T. et al. Cost Effective and Scalable Synthesis of Supported Au Nanoparticles for the Electroreduction of CO 2 to CO. Sci. Adv. Mater. 9, 888–895 (2017). 3. Wu, J. et al. Electrochemical Reduction of Carbon Dioxide II. Design, Assembly, and Performance of Low Temperature Full Electrochemical Cells. J. Electrochem. Soc. 160, F953–F957 (2013). 4. Kim, B., Hillman, F., Ariyoshi, M., Fujikawa, S. & Kenis, P. J. A. Effects of composition of the micro porous layer and the substrate on performance in the electrochemical reduction of CO2 to CO. J. Power Sources 312, 192–198 (2016). 5. Liu, Z. et al. Electrochemical generation of syngas from water and carbon dioxide at industrially important rates. J. CO2 Util. 15, 50–56 (2016).

Electroreduction of Carbon Monoxide Over a Copper Nanocube Catalyst: Surface Structure and pH Dependence on Selectivity

AbstractThe activity and selectivity for CO2/CO reduction over Cu electrodes is strongly dependent on the local surface structure of the catalyst and the pH of the electrolyte. Here we investigate a unique, Cu nanocube surface (CuCube) as a CO reduction electrode under neutral and basic pH by using online electrochemical mass spectroscopy (OLEMS) to determine the onset potentials and relative intensities of methane and ethylene production. To relate the unique selectivity to the surface structure, the CuCube surface reactivity is compared to polycrystalline Cu and three single crystals under the same reaction conditions. We find that the high selectivity for ethylene over the CuCube surface is most comparable to the Cu(1 0 0) surface, which has a cubic unit cell. However, the suppression of methane production over CuCube is unique to that particular surface. A basic pH is shown to enhance ethylene selectivity on all surfaces, and again the CuCube surface is unique.

Electroreduction of carbon monoxide on palladium electrodeposits in solutions containing copper ions

It is shown that the electroreduction of CO proceeds on electrolytic deposits of palladium (edPd) in 0.5 M H2SO4 + (1–5) mM CuSO4 + CO(sat) solutions at the potentials more positive than the Cu2+/Cu equilibrium potential. Among the CO reduction products, methanol and formaldehyde are identified. The current efficiency with respect to CH3OH exceeds 75% on edPd formed in 1% PdCl2+0.5 M H2SO4 solutions. In addition, Cu+ ions, which probably form complexes with CO, are detected in the solution and are assumed to play the role of intermediate species in the mediator catalysis along with copper adatoms.

Copper Ion Catalyzed Electroreduction of Carbon Monoxide on Iridium Electrode

Substantial cathodic currents are observed on iridium electroplates in 0.5 M H2SO4 + (0.001–0.005 M) CuSO4 + CO (sat) at potentials positive with respect to the Cu/Cu2+ equilibrium potential. These currents are shown to correspond to electroreduction of both CO and Cu2+ ions to Cu+, where the latter ions are formed in amounts indicating the formation of complexes. Among the products of CO reduction, methanol and formaldehyde are identified. A possible mechanism of CO reduction is discussed. It is assumed that both copper adatoms and Cu+ ions can play the role of intermediates in the mediator catalysis.

The electroreduction of carbon monoxide at metal/zirconium hydrogen phosphate interfaces

The present study investigates the electroreduction of carbon monoxide at the M/Zr(HPO 4 ) 2 •H 2 O interface (where M=Cu, Zn, Cd, Fe, and brass (Cu60/Zn40))

Performance characteristics of zinc-N,N?-dichlorodimethyl hydantoin primary cell

The present study investigates the electroreduction of carbon monoxide at the M/Zr(HPO 4 ) 2 •H 2 O interface (where M=Cu, Zn, Cd, Fe, and brass (Cu60/Zn40))

Electroreduction of carbon monoxide in aqueous solutions of molybdenum (III)-pyrocatechol complex

1. Molybdenum (III) complexes with pyrocatechol catalyze the electrochemical reduction of CO on a mercury cathode in aqueous solution to give C1-C4 hydrocarbons. 2. The reaction proceeds in a thin preelectrode layer and is accompanied by the parallel liberation of hydrogen.