Showing papers on "Copper published in 2021"
26 Jul 2021
TL;DR: In this article, the authors studied CO2 reduction on gold electrodes through cyclic voltammetry and showed that, without a metal cation, the reaction does not take place in a pure 1mM H2SO4 electrolyte.
Abstract: The electrocatalytic reduction of carbon dioxide is widely studied for the sustainable production of fuels and chemicals. Metal ions in the electrolyte influence the reaction performance, although their main role is under discussion. Here we studied CO2 reduction on gold electrodes through cyclic voltammetry and showed that, without a metal cation, the reaction does not take place in a pure 1 mM H2SO4 electrolyte. We further investigated the CO2 reduction with and without metal cations in solution using scanning electrochemical microscopy in the surface-generation tip-collection mode with a platinum ultramicroelectrode as a CO and H2 sensor. CO is only produced on gold, silver or copper if a metal cation is added to the electrolyte. Density functional theory simulations confirmed that partially desolvated metal cations stabilize the CO2– intermediate via a short-range electrostatic interaction, which enables its reduction. Overall, our results redefine the reaction mechanism and provide definitive evidence that positively charged species from the electrolyte are key to stabilize the crucial reaction intermediate.
247 citations
TL;DR: In this article, a hybrid photocatalyst (CuOX@p-ZnO) with CuOX uniformly dispersed among polycrystalline ZnO was synthesized upon illumination, the catalyst exhibited the ability to reduce CO2 to C2H4 with a 329% selectivity, and the evolution rate was 27 μmol·g-1·h-1 with water as a hole scavenger.
Abstract: To realize the evolution of C2+ hydrocarbons like C2H4 from CO2 reduction in photocatalytic systems remains a great challenge, owing to the gap between the relatively lower efficiency of multielectron transfer in photocatalysis and the sluggish kinetics of C-C coupling Herein, with Cu-doped zeolitic imidazolate framework-8 (ZIF-8) as a precursor, a hybrid photocatalyst (CuOX@p-ZnO) with CuOX uniformly dispersed among polycrystalline ZnO was synthesized Upon illumination, the catalyst exhibited the ability to reduce CO2 to C2H4 with a 329% selectivity, and the evolution rate was 27 μmol·g-1·h-1 with water as a hole scavenger and as high as 223 μmol·g-1·h-1 in the presence of triethylamine as a sacrificial agent, all of which have rarely been achieved in photocatalytic systems The X-ray absorption fine structure spectra coupled with in situ FT-IR studies reveal that, in the original catalyst, Cu mainly existed in the form of CuO, while a unique Cu+ surface layer upon the CuO matrix was formed during the photocatalytic reaction, and this surface Cu+ site is the active site to anchor the in situ generated CO and further perform C-C coupling to form C2H4 The C-C coupling intermediate *OC-COH was experimentally identified by in situ FT-IR studies for the first time during photocatalytic CO2 reduction Moreover, theoretical calculations further showed the critical role of such Cu+ sites in strengthening the binding of *CO and stabilizing the C-C coupling intermediate This work uncovers a new paradigm to achieve the reduction of CO2 to C2+ hydrocarbons in a photocatalytic system
148 citations
Tianjin University of Technology1, University of Jinan2, University of Science and Technology Beijing3, Civil Aviation University of China4, Shenzhen University5, SLAC National Accelerator Laboratory6, Lanzhou University of Technology7, Chinese Academy of Sciences8, University of Electronic Science and Technology of China9
TL;DR: In this article, a single atom copper catalyst supported on MXene with high CO reduction performance and stability is presented, achieving an ultra high selectivity of 98% for the formation of multicarbon products.
Abstract: Electrochemical carbon monoxide reduction is a promising strategy for the production of value-added multicarbon compounds, albeit yielding diverse products with low selectivities and Faradaic efficiencies. Here, copper single atoms anchored to Ti3C2Tx MXene nanosheets are firstly demonstrated as effective and robust catalysts for electrochemical carbon monoxide reduction, achieving an ultrahigh selectivity of 98% for the formation of multicarbon products. Particularly, it exhibits a high Faradaic efficiency of 71% towards ethylene at −0.7 V versus the reversible hydrogen electrode, superior to the previously reported copper-based catalysts. Besides, it shows a stable activity during the 68-h electrolysis. Theoretical simulations reveal that atomically dispersed Cu–O3 sites favor the C–C coupling of carbon monoxide molecules to generate the key *CO-CHO species, and then induce the decreased free energy barrier of the potential-determining step, thus accounting for the high activity and selectivity of copper single atoms for carbon monoxide reduction. Electrochemical carbon monoxide reduction is a promising strategy to yield valuable multicarbon products but low selectivities and Faradaic efficiencies are common. Here the authors show single atom copper catalyst supported on MXene with high CO reduction performance and stability.
127 citations
TL;DR: In this article, the authors designed a Cu-CuI composite catalyst with abundant Cu0 /Cu+ interfaces by physically mixing Cu nanoparticles and CuI powders, which achieved a remarkable C2+ partial current density of 591 mA cm-2 at -10 V vs reversible hydrogen electrode in a flow cell.
Abstract: Electrochemical CO2 reduction reaction (CO2 RR) to multicarbon hydrocarbon and oxygenate (C2+ ) products with high energy density and wide availability is of great importance, as it provides a promising way to achieve the renewable energy storage and close the carbon cycle Herein we design a Cu-CuI composite catalyst with abundant Cu0 /Cu+ interfaces by physically mixing Cu nanoparticles and CuI powders The composite catalyst achieves a remarkable C2+ partial current density of 591 mA cm-2 at -10 V vs reversible hydrogen electrode in a flow cell, substantially higher than Cu (329 mA cm-2 ) and CuI (96 mA cm-2 ) counterparts Induced by alkaline electrolyte and applied potential, the Cu-CuI composite catalyst undergoes significant reconstruction under CO2 RR conditions The high-rate C2+ production over Cu-CuI is ascribed to the presence of residual Cu+ and adsorbed iodine species which improve CO adsorption and facilitate C-C coupling
120 citations
TL;DR: In this paper, a bioinspired copper catalyst on a gas diffusion layer that mimics the unique hierarchical structuring of Setaria's hydrophobic leaves was proposed, which can not only trap more CO close to the active copper surface but also effectively resist electrolyte flooding even under high-rate operation.
Abstract: Copper is currently the material with the most promise as catalyst to drive carbon dioxide (CO₂) electroreduction to produce value-added multicarbon (C₂₊) compounds. However, a copper catalyst on a carbon-based gas diffusion layer electrode often has poor stability—especially when performing at high current densities—owing to electrolyte flooding caused by the hydrophobicity decrease of the gas diffusion layer during operation. Here, we report a bioinspired copper catalyst on a gas diffusion layer that mimics the unique hierarchical structuring of Setaria’s hydrophobic leaves. This hierarchical copper structure endows the CO₂ reduction electrode with sufficient hydrophobicity to build a robust gas–liquid–solid triple-phase boundary, which can not only trap more CO₂ close to the active copper surface but also effectively resist electrolyte flooding even under high-rate operation. We consequently achieved a high C₂₊ production rate of 255 ± 5.7 mA cm–² with a 64 ± 1.4% faradaic efficiency, as well as outstanding operational stability at 300 mA cm–² over 45 h in a flow reactor, largely outperforming its wettable copper counterparts.
116 citations
TL;DR: In this paper, 2-mercaptobenzimidazole (MBI) and octylphosphonic acid (OPA) and their binary combinations on copper and aluminium were investigated by electrochemical methods, whereas the bonding of inhibitors was scrutinized by XPS and FTIR spectroscopies, wettability measurements, and DFT calculations.
109 citations
TL;DR: In this article, the authors used copper(I)-alkynyl chemistry within an ultra-microporous MOF (CuI @UiO-66-(COOH)2 ) to achieve ultrahigh C2 H2 /CO2 separation selectivity.
Abstract: Separation of acetylene from carbon dioxide remains a daunting challenge because of their very similar molecular sizes and physical properties. We herein report the first example of using copper(I)-alkynyl chemistry within an ultra-microporous MOF (CuI @UiO-66-(COOH)2 ) to achieve ultrahigh C2 H2 /CO2 separation selectivity. The anchored CuI ions on the pore surfaces can specifically and strongly interact with C2 H2 molecule through copper(I)-alkynyl π-complexation and thus rapidly adsorb large amount of C2 H2 at low-pressure region, while effectively reduce CO2 uptake due to the small pore sizes. This material thus exhibits the record high C2 H2 /CO2 selectivity of 185 at ambient conditions, significantly higher than the previous benchmark ZJU-74a (36.5) and ATC-Cu (53.6). Theoretical calculations reveal that the unique π-complexation between CuI and C2 H2 mainly contributes to the ultra-strong C2 H2 binding affinity and record selectivity. The exceptional separation performance was evidenced by breakthrough experiments for C2 H2 /CO2 gas mixtures. This work suggests a new perspective to functionalizing MOFs with copper(I)-alkynyl chemistry for highly selective separation of C2 H2 over CO2 .
101 citations
TL;DR: The results show the complex interrelation of the morphology, structure, defect density, applied potential, and electrolyte in copper CO2RR catalysts.
Abstract: Electrochemical AFM is a powerful tool for the real-space characterization of catalysts under realistic electrochemical CO2 reduction (CO2 RR) conditions. The evolution of structural features ranging from the micrometer to the atomic scale could be resolved during CO2 RR. Using Cu(100) as model surface, distinct nanoscale surface morphologies and their potential-dependent transformations from granular to smoothly curved mound-pit surfaces or structures with rectangular terraces are revealed during CO2 RR in 0.1 m KHCO3 . The density of undercoordinated copper sites during CO2 RR is shown to increase with decreasing potential. In situ atomic-scale imaging reveals specific adsorption occurring at distinct cathodic potentials impacting the observed catalyst structure. These results show the complex interrelation of the morphology, structure, defect density, applied potential, and electrolyte in copper CO2 RR catalysts.
94 citations
TL;DR: Time-Resolved Surface Enhanced Raman Spectroscopy (TR-SERS) was used to monitor CO2RR over Cu surfaces with sub-second time resolution as mentioned in this paper.
Abstract: Electrocatalytic reduction of carbon dioxide (CO2) into value-added products (e.g., ethylene) is a promising approach for greenhouse gas mitigation, but many details of electrocatalytic CO2 reduction reactions (CO2RR) remain elusive. Raman spectroscopy is suitable for in situ characterization of CO2RR mechanisms, but the low signal intensity and resulting poor time resolution (often up to minutes) hampers the application of conventional Raman spectroscopy for the study of the dynamic CO2 reduction reaction, which requires sub-second time resolution. By using Time-Resolved Surface Enhanced Raman Spectroscopy (TR-SERS) we were able to successfully monitor CO2RR over Cu surfaces with sub-second time resolution. Anodic treatment at 1.55 V vs. the reversible hydrogen electrode (RHE) and subsequent surface oxide reduction (below -0.4 V vs. RHE) induced roughening of the Cu electrode surface, which resulted in hot-spots for TR-SERS, enhanced time resolution (down to ~ 0.7 s) and improved CO2RR efficiency (i.e., four-fold increase in ethylene faradaic efficiency). With TR-SERS, the initial formation of hot-spots for SERS and CO2RR was followed (<7 s), after which a stable copper surface surrounded by increased local alkalinity was formed. Our measurements revealed that a highly dynamic CO intermediate, with a characteristic vibration below 2060 cm-1, is related to C-C coupling and ethylene production (-0.9 V vs. RHE), whereas lower cathodic bias (-0.7 V vs. RHE) resulted in gaseous CO production from isolated and static CO surface species with a distinct vibration at 2092 cm-1. Our results provide valuable time-resolved insights into the dynamic nature of the electrode surface and adsorbed intermediates during CO2 electrochemical reduction on copper and showcase the potential of TR-SERS in copper-based electrocatalysis to follow reaction dynamics.
92 citations
TL;DR: In this article, a functionally graded material (FGM) part was fabricated by depositing a Cu-based alloy on top of a high strength low alloy (HSLA) steel by twin-wire and arc additive manufacturing (TWAAM).
92 citations
TL;DR: In this article, an excellent catalytic activity of a 2D copper-based conductive MOF, copper tetrahydroxyquinone (CuTHQ), is reported for aqueous CO2 reduction reaction (CO2 RR) at low overpotentials.
Abstract: Metal-organic frameworks (MOFs) are promising materials for electrocatalysis; however, lack of electrical conductivity in the majority of existing MOFs limits their effective utilization in the field Herein, an excellent catalytic activity of a 2D copper (Cu)-based conductive MOF, copper tetrahydroxyquinone (CuTHQ), is reported for aqueous CO2 reduction reaction (CO2 RR) at low overpotentials It is revealed that CuTHQ nanoflakes (NFs) with an average lateral size of 140 nm exhibit a negligible overpotential of 16 mV for the activation of this reaction, a high current density of ≈173 mA cm-2 at -045 V versus RHE, an average Faradaic efficiency (FE) of ≈91% toward CO production, and a remarkable turnover frequency as high as ≈2082 s-1 In the low overpotential range, the obtained CO formation current density is more than 35 and 25 times higher compared to state-of-the-art MOF and MOF-derived catalysts, respectively The operando Cu K-edge X-ray absorption near edge spectroscopy and density functional theory calculations reveal the existence of reduced Cu (Cu+ ) during CO2 RR which reversibly returns to Cu2+ after the reaction The outstanding CO2 catalytic functionality of conductive MOFs (c-MOFs) can open a way toward high-energy-density electrochemical systems
TL;DR: Carbon/copper composites are widely used in collector brushes, pantograph sliders, collector shoes and other fields due to their excellent mechanical friction, wear, thermal conductivity and electricity as discussed by the authors.
Abstract: Carbon/copper composites are widely used in collector brushes, pantograph sliders, collector shoes and other fields due to their excellent mechanical friction, wear, thermal conductivity and electr...
TL;DR: In this article, the only metal capable of catalyzing CO2 reduction to multicarbon products is shown to be the metal Cu, and its catalytic performance is determined collectively by a number of para...
Abstract: Cu is in the spotlight as it represents the only metal capable of catalyzing CO2 reduction to multicarbon products. However, its catalytic performance is determined collectively by a number of para...
TL;DR: The understanding of the maturation of mitochondrial copper enzymes, the roles of mitochondrial signals in regulating cellular copper content, the proposed mechanisms of copper transport into the organelle and the evolutionary origins of copper homeostasis pathways are detailed.
TL;DR: In this article, a binder-free composite electrode (Cu3P/CF) was first prepared by direct growth of copper phosphide on copper foam and then applied to electrochemical NO3- reduction.
TL;DR: The facet effect of copper crystal to promote CO adsorption and C-C coupling and consequently yield a superior selectivity for C2+ products is described and paves the way for the practical application of electrocatalytic or solar-driven CO2 reduction.
Abstract: Copper can efficiently electro-catalyze carbon dioxide reduction to C2+ products (C2 H4 , C2 H5 OH, n-propanol). However, the correlation between the activity and active sites remains ambiguous, impeding further improvements in their performance. The facet effect of copper crystals to promote CO adsorption and C-C coupling and consequently yield a superior selectivity for C2+ products is described. We achieve a high Faradaic efficiency (FE) of 87 % and a large partial current density of 217 mA cm-2 toward C2+ products on Cu(OH)2 -D at only -0.54 V versus the reversible hydrogen electrode in a flow-cell electrolyzer. With further coupled to a Si solar cell, record-high solar conversion efficiencies of 4.47 % and 6.4 % are achieved for C2 H4 and C2+ products, respectively. This study provides an in-depth understanding of the selective formation of C2+ products on Cu and paves the way for the practical application of electrocatalytic or solar-driven CO2 reduction.
TL;DR: In this article, the application of metallic catalyst-H2O2 systems in the heterogeneous Fenton process is reviewed and the performance of each metallic catalyst has unique redox properties due to metal oxidation state.
Abstract: Innovations in water technology are needed to solve challenges of climate change, resource shortages, emerging contaminants, urbanization, sustainable development and demographic changes. In particular, conventional techniques of wastewater treatment are limited by the presence of poorly biodegradable organic matter. Alternatively, recent Fenton, Fenton-like and hybrid processes appear successful for cleaning of different types of liquid wastewaters. Here, we review the application of metallic catalyst-H2O2 systems in the heterogeneous Fenton process. Each metallic catalyst-H2O2 system has unique redox properties due to metal oxidation state. Solution pH is a major influencing factor. Catalysts made of iron and cerium form stable complexes with oxidation products and H2O2, thus resulting in reduced activities. Copper forms transitory complexes with oxidation products, but copper catalytic activity is restored during the reaction. Silver and manganese do not form complexes. The catalyst performance for degradation and mineralization decreases in the order: manganese, copper, iron, silver, cerium, yet the easiness of practical application decreases in the order: copper, manganese, iron, silver, cerium.
TL;DR: In this paper, the laser-based powder bed fusion (L -PBF) processing behavior of pure copper powder is evaluated by employing a conventional infrared fiber laser with a wavelength of 1080nm, a small focal spot diameter of 37.5 µm, and power levels up to 500 µm.
Abstract: In this article, the laser-based powder bed fusion ( L -PBF) processing behavior of pure copper powder is evaluated by employing a conventional infrared fiber laser with a wavelength of 1080 nm, a small focal spot diameter of 37.5 µm, and power levels up to 500 W. It is shown that bulk solid copper parts with near full density (ρ Archimedes = 99.3 ± 0.2%, ρ Optical = 99.8 ± 0.1%) can be produced using a laser power of 500 W for the chosen combination of powder particle size, L -PBF settings, and pure copper baseplate. Moreover, at 500 W, parts with a relative density exceeding 99% are manufactured within a volumetric energy density window of 230–310 J/mm3, while laser power levels below 500 W did not produce parts with a relative density above 99%. An analytical model is used to elucidate the L -PBF processing behavior, wherein both conduction and keyhole regimes corresponding to the employed L -PBF settings are identified. The analytical model-based results predict that the bulk solid copper parts with near full density are produced in a keyhole regime prior to the onset of keyhole-induced porosity, which is in accordance with the porosity types observed in the parts. The L -PBF fabricated copper parts exhibit an electrical conductivity of 94 ± 1% compared to the international annealed copper standard (IACS) and demonstrate a tensile strength of 211 ± 4 MPa, a yield strength of 122 ± 1 MPa, and an elongation at break of 43 ± 3% in the as-built condition.
TL;DR: In this article, the anti-corrosion efficiency of DDD and DTDD were as high as 99.6% and 98.9%, respectively, in 0.5 mol/L H2SO4 media.
TL;DR: In this article, a green method was used to synthesize powders activated carbon and granular activated carbon composites with magnetite nanoparticles (Fe3O4) using green tea extract as reducing agent.
TL;DR: In this article, the corrosion characteristics of super-hydrophobic copper surfaces with multiscale asperities formed inherently on a copper substrate, using a facile, low energy, electrodepostion method, were investigated.
TL;DR: In this paper, the authors show that micromolar concentrations of iron(III) and copper(II) are more important sinks for ascorbic acid (both AH2 and AH-) than reactive oxygen species.
Abstract: Ascorbic acid is among the most abundant antioxidants in the lung, where it likely plays a key role in the mechanism by which particulate air pollution initiates a biological response. Because ascorbic acid is a highly redox active species, it engages in a far more complex web of reactions than a typical organic molecule, reacting with oxidants such as the hydroxyl radical as well as redox-active transition metals such as iron and copper. The literature provides a solid outline for this chemistry, but there are large disagreements about mechanisms, stoichiometries and reaction rates, particularly for the transition metal reactions. Here we synthesize the literature, develop a chemical kinetics model, and use seven sets of laboratory measurements to constrain mechanisms for the iron and copper reactions and derive key rate constants. We find that micromolar concentrations of iron(III) and copper(II) are more important sinks for ascorbic acid (both AH2 and AH-) than reactive oxygen species. The iron and copper reactions are catalytic rather than redox reactions, and have unit stoichiometries: Fe(III)/Cu(II) + AH2/AH- + O2 → Fe(III)/Cu(II) + H2O2 + products. Rate constants are 5.7 × 104 and 4.7 × 104 M-2 s-1 for Fe(III) + AH2/AH- and 7.7 × 104 and 2.8 × 106 M-2 s-1 for Cu(II) + AH2/AH-, respectively.
TL;DR: In this paper, a new hydrometallurgical route for the technically feasible recycling of copper and gold from waste printed circuit boards (WPCBs) of mobile phones is presented.
TL;DR: In this paper, surface sulfur-doped and -adsorbed low-coordinated copper nanowire sponges are designedly synthesized via in situ electroreduction of copper sulfide and enable electrocatalytic alkyne semi-hydrogenation with over 99% selectivity using water as the hydrogen source.
Abstract: Electrocatalytic alkyne semi-hydrogenation to alkenes with water as the hydrogen source using a low-cost noble-metal-free catalyst is highly desirable but challenging because of their over-hydrogenation to undesired alkanes. Here, we propose that an ideal catalyst should have the appropriate binding energy with active atomic hydrogen (H*) from water electrolysis and a weaker adsorption with an alkene, thus promoting alkyne semi-hydrogenation and avoiding over-hydrogenation. So, surface sulfur-doped and -adsorbed low-coordinated copper nanowire sponges are designedly synthesized via in situ electroreduction of copper sulfide and enable electrocatalytic alkyne semi-hydrogenation with over 99% selectivity using water as the hydrogen source, outperforming a copper counterpart without surface sulfur. Sulfur anion-hydrated cation (S2−-K+(H2O)n) networks between the surface adsorbed S2− and K+ in the KOH electrolyte boost the production of active H* from water electrolysis. And the trace doping of sulfur weakens the alkene adsorption, avoiding over-hydrogenation. Our catalyst also shows wide substrate scopes, up to 99% alkenes selectivity, good reducible groups compatibility, and easily synthesized deuterated alkenes, highlighting the promising potential of this method. Highly selective electrocatalytic semi-hydrogenation of alkynes over a noble-metal-free catalyst is highly desirable. Here, authors synthesize sulfur-containing copper nanowire sponges for selective electrocatalytic alkyne semi-hydrogenation using water as the hydrogen source.
TL;DR: In this article, the NH3-SCR reaction was investigated on Cu-exchanged zeolites and the results showed that the formation of the [Cu(OH)(NH3)2(NO)]+ mixed ligand species is governed by the competition between the O2− and NH3 ligands.
Abstract: The catalytic activity and stability of Cu-exchanged zeolites Cu-ZSM-5 (MFI topology), Cu-TNU-9 (TUN), Cu-FER (FER) and steamed Cu-Y (FAU) were evaluated in the selective catalytic NO reduction by ammonia (NH3-SCR). The NH3-SCR activity of the investigated catalysts strongly depended on the feed composition, i.e., the presence of H2O (5.0 Vol.-% of H2O). The catalysts revealed high stability during 24 h of NH3-SCR reaction, also in the presence of water vapour. DR UV–vis and FT-IR with probe molecules (CO or NO) showed the presence of isolated Cu+/Cu2+ and aggregated copper oxide species. Although Cu-ZSM-5 is less active than Cu-TNU-9 in catalysing NO oxidation to NO2, both catalysts revealed similar activity in the NH3-SCR reaction. Applying Rapid-Scan FT-IR spectroscopy and 2D COS analysis the reaction mechanism of NH3-SCR on Cu-exchanged zeolites was investigated. It is proposed that NH3-SCR over the studied Cu-exchanged catalysts proceeds via [Cu(OH)(NH3)2(NO)]+ intermediates followed by the reduction of Cu(II) to Cu(I). The differentiated speciation of copper sites is reflected in their various susceptibility for the reduction and finally affects the catalytic activity and stability of the zeolitic catalysts. The formation of the [Cu(OH)(NH3)2(NO)]+ mixed ligand species is governed by the competition between the O2− and NH3 ligands. Also the stability of the forms initiating NH3-SCR, i.e., [Cu(NH3)4]2+, [Cu(OH)(NH3)3]+ and [Cu(NH3)2]+, is ruled by the confine interaction of ammonia molecules, which can be both adsorbed on a protonic site and ligated to copper sites with the framework oxygen atoms.
TL;DR: A comparative study of flash smelting furnace (FSF) slag and its flotation products (concentrate and tailing) reveals the factors affecting the separation of copper and arsenic in the beneficiation process from the perspective of mineralogy and morphology.
TL;DR: A review of the development and current state of GRCop or Glenn Research copper alloys with emphasis on Cu-8Cr-4Nb (at%), or GRCops-84, and C... is given in this article.
Abstract: This review examines the development and current state of Cu-rich Cu–Cr–Nb alloys commonly referred to as GRCop or Glenn Research copper alloys with emphasis on Cu–8Cr–4Nb (at%), or GRCop-84, and C...
TL;DR: In this article, a coordination-enabled galvanic replacement method was used to decorate atomic Ni clusters on defect-rich Cu surface to provide the first Ni/Cu bimetallic system that significantly enhances the production of C2 products from electrocatalytic CO2 reduction.
Abstract: This work describes a coordination enabled galvanic replacement method to decorate atomic Ni clusters on defect-rich Cu surface to provide the first Ni/Cu bimetallic system that significantly enhances the production of C2 products from electrocatalytic CO2 reduction. Specifically, with a surface Ni/Cu ratio of 0.82 %, a 7-fold increase in the selectivity for C2 products was found in comparison with pristine Cu. Density functional theory calculations reveal that the rate determining step for *CO formation changes from the formation of *COOH on copper to the chemisorption of CO2 on Ni decorated surfaces. An alteration of binding sites from Ni-Ni bridge for *CO2 and *COOH to Ni-Cu bridge for *CO is discovered and is proposed to favor the key C C coupling step. The catalytic mechanism demonstrated in the Cu-Ni system points to the new directions for the development of advanced bimetallic electrocatalysts for producing multi-carbon materials from CO2 reduction.