Onset Potential Research Articles

Hot Injection Assisted Electronically Modulated Twin and Grain Boundary Rich Sub-2 nm Pt3Co Alloy Resistant to Phosphate Ion for PEMFCs.

Modulation of the electronic d-band center, structural defects (line defects), and particle size of Pt3Co alloy electrocatalyst have huge significance in elevating its electrochemical oxygen reduction reaction activity. Deviating from traditional high-temperature strategies, the current work focuses on ripening these benefits by implying a simple economically viable hot-injection-assisted modified polyol process. A conclusive control over decrementing particle size starting from 2.7 to 1.3nm, an increasing degree of strain (twin boundary), and shifting of the d-band center away from the Fermi level are obtained via varying the temperature to which the solution is injected. The catalyst prepared via the injection at 200 °C (Pt3Co(1.3 t,g-b)/fVC-200) has delivered an electrochemical surface area of 84 m2 with the onset and half-wave potentials of 0.980 and 0.858V, respectively, versus RHE and a limiting current of -6.0mA cm-2 with stability till 20k cycles. In the high-temperature proton exchange membrane fuel cell Pt3Co(1.3 t,g-b)/fVC-200-based cell has outperformed Pt/C rendering 600 mWcm-2 under H2-Air compared to 529 mWcm-2 of Pt/C with 20% lower Pt loading and double the stability due to enhanced resistance toward phosphoric acid for accelerated voltage cycling. A similar enhancement is seen while employing the catalyst for low-temperature fuel cells.

High-Entropy Nitrides as Superior Electrocatalysts: Unveiling the Role of Entropy in Enhanced Performance.

High-entropy nitrides (HENs) are emerging as promising electrocatalysts due to their diverse elemental composition, tunable electrochemical properties, and a wide range of active sites that enhance adsorption and oxidation reactions. However, the unclear role of entropy has limited their full potential in electrocatalysis. In this study, we introduce a novel and straightforward method for synthesizing (CoNiCuVW)N with variable entropy levels using halite as a molten salt. By exploiting the synergistic effects of multiple metal components, we achieve robust bonding between the N-doped carbon substrate and HEN nanoparticles, resulting in a homogeneous elements distribution. This uniformity leads to exceptional catalytic performance for the oxygen reduction reaction (ORR) in alkaline electrolytes, with an onset potential of 0.96 V and a half-wave potential of 0.91 V. Additionally, HEN-based zinc-air batteries exhibit impressive performance, achieving 1.55 V and maintaining 60% roundtrip efficiency over approximately 400 cycles. Density functional theory (DFT) calculations suggest that the high-entropy, homogeneous distribution of elements enhances active site availability, modulates electronic structure, and optimizes kinetics, thereby lowering reaction barriers during the ORR. This work not only facilitates the development of structurally ordered HEN nanoparticles but also lays the foundation for further exploration in electrochemical applications.

Modulating the Cavity Size of Carbon Nanobelts for Enhanced Oxygen Reduction Reaction.

The preactivation of reactants within the cavities of carbon nanotubular materials has remained largely unexplored due to the scarcity of materials with well-defined sizes and precisely engineered doping sites. Herein, we demonstrate that the catalytic activity toward the oxygen reduction reaction (ORR) is primarily governed by the cavity sizes of well-defined nanobelt materials with precisely doped sp2-nitrogen atoms. Our results show that the confinement effect induced by cavity size and the electron-rich chemical environment within the cavity are crucial for O2 adsorption and preactivation, leading to enhanced catalytic activity. Belt2, with its medium-sized cavity (6.3 Å), exhibits superior ORR catalytic performance compared to Belt1 with its narrower cavity and Belt3/Belt4 with its larger cavities. Notably, Belt2 achieves high half-wave and onset potentials of 0.84 and 0.97 V, respectively, along with an open-circuit voltage of 1.32 V and a peak power density of 181 mW cm-2 in a zinc-air battery. This work not only provides a deeper understanding of the geometric factors influencing the ORR electrocatalysis of nanocarbon materials but also offers insights into the future design of nanocarbon electrocatalysts for enhancing catalytic efficiency. These findings may also be beneficial for other energy conversion and catalytic materials.

A HER‐Inhibiting Layer Based on M‐H Bond Regulation for Achieving Stable Zinc Anodes in Aqueous Zinc‐Ion Batteries

AbstractA hydrogen evolution reaction (HER) Strategy is developed through material design to address the persistent challenge of the HER at the zinc anode. Unlike previous strategies, first‐principles calculations are used to screen the low‐coordinated Nb₂C MXene as the inhibitory medium. By taking advantage of the dual merits of its high |ΔG*H| (1.03 eV) and excellent structural stability, the HER‐Inhibiting layer Nb₂C@Znp is designed, which demonstrates the following key advancements: I) The onset potential for hydrogen evolution of 1.97 V (vs Zn2⁺/Zn) is achieved, representing a positive shift of 0.51 V compared with the bare zinc anode; II) It shows excellent cycling stability, being able to maintain for 2000 h at a current density of 2 mA cm⁻2 and for 700 h at a current density of 10 mA cm⁻2. III) The simultaneous inhibition of the hydrogen evolution reaction and the mitigation of dendrite growth are achieved through the regulation of the interfacial electron structure. Mechanistic studies indicate that the Nb₂C matrix weakens the bond energy of the M‐H bond, and at the same time creates preferential migration channels for Zn2⁺, achieving a synergistic effect of inhibiting hydrogen adsorption and homogenizing zinc deposition, which greatly improves the CE and cycling stability.

Remote sensing-based flash flood mapping and damage assessment in Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan.

Flash floods pose significant risks due to their rapid onset and destructive potential, causing an estimated 5000 fatalities and billions of dollars in damage annually worldwide. The Dera Ismail Khan district in Pakistan, highly susceptible to flooding, highlights the urgent need for a robust flood risk management framework, especially in the aftermath of the devastating 2022 flash flood, the most severe on record for the region. This study employed remote sensing (RS) and Geographic Information System (GIS) techniques to analyze the flood's spatiotemporal dynamics and assess the resulting damage. Flood maps were generated using Landsat 9 images using the Modified Normalized Difference Water Index (MNDWI) and classified land use using the supervised maximum likelihood method. The findings revealed that the flood inundated approximately 2876 km2 for about 1.5months, significantly impacting agricultural and urban areas, with widespread damage to crops and infrastructure. This research highlights the importance of spatiotemporal analysis in improving flood management in Dera Ismail Khan and can serve as a model for similar assessments in other regions globally.

Coordination Tailoring of Pt Single‐Atom Catalysts at Room Temperature and Their Exceptional Performance in Hydrogen Evolution Reaction

ABSTRACTSingle‐atom catalysts (SACs) have garnered interest in designing their ligand environments, facilitating the modification of single catalytic sites toward high activity and selectivity. Despite various synthetic approaches, it remains challenging to achieve a catalytically favorable coordination structure simultaneously with the feasible formation of SACs at low temperatures. Here, a new type of coordination structure for Pt SACs is introduced to offer a highly efficient hydrogen evolution reaction (HER) catalyst, where Pt SACs are readily fabricated by atomically confining PtCl2 on chemically driven NO2 sites in two‐dimensional nitrogen‐doped carbon nanosheets at room temperature. The resultant Pt SACs form the NO2–Pt–Cl2 coordination structure with an atomic dispersion, as revealed by X‐ray spectroscopy and transmission electron microscopy investigations. Moreover, our first‐principles density functional theory (DFT) calculations show strong interactions in the coordination by computing the binding energy and charge density difference between PtCl2 and NO2. Pt SACs, established on the NO2‐functionalized carbon support, demonstrate the onset potential of 25 mV, Tafel slope of 40 mV dec−1, and high specific activity of 1.35 A mgPt−1. Importantly, the Pt SACs also exhibit long‐term stability up to 110 h, which is a significant advance in the field of single‐atom Pt catalysts. The newly developed coordination structure of Pt SACs features a single Pt active center, providing hydrogen binding ability comparable to that of Pt(111), enhanced long‐term durability due to strong metal‐support interactions, and the advantage of room‐temperature fabrication.

Electrooxidation of 2‐Propanol on Mono‐ and Bi‐Metallic Noble Metal Nanoparticles in Alkaline Studied with Real‐Time Product and Dissolution Characterization

AbstractThe selective electrochemical oxidation of 2‐propanol to acetone can be used in fuel cells to deliver low‐carbon electricity and efficiently utilize hydrogen that is stored in liquid organic hydrogen carrier molecules. Here we study the electrooxidation of 2‐propanol in alkaline electrolyte, on various commercially available carbon‐supported mono‐ and bi‐metallic noble metal nanoparticles. We use voltammetry to compare the activity of different catalysts, and we combine a flow cell with real‐time analytics to monitor the products of the reaction and the dissolution of metal atoms in the presence and absence of 2‐propanol. While acetone if formed on all catalysts, our results show that the onset potential is the lowest for PtRu/C, Rh/C and PdRh/C, but the oxidation current for the latter reaches a much higher value before the surface is passivated, suggesting that PdRh/C would be preferred in an alkaline fuel cell that is fed with 2‐propanol. Online dissolution monitoring suggests that the anode in a 2‐propanol fuel cell should not be exposed to potentials above ca. +0.8 V during transient operation, i. e., during startup/shutdown conditions, to prevent dissolution of palladium and rhodium from the catalyst surface.

Fabrication and characterization of Ni-based electrodes for improved NiZn battery performance

In this study, a hydrothermal method was used to synthesize nickel hydroxide (Ni(OH)2) powders, which are active materials for use in nickel (Ni) electrodes located in nickel-zinc (NiZn) batteries. X-ray diffraction (XRD), scanning electron microscopy (SEM), zeta potential, Brunauer-Emmett-Teller (BET), and electrochemical characterization were used to characterize the cathode material in the prepared Ni electrodes. These results showed a β-phase Ni(OH)2 nanosphere with a well-crystalline structure. The electrochemical test results indicated the Ni electrode has a stable cyclic cycle in the half-cell. Based on the electrochemical performance results, the Ni electrode with Ni(OH)2, which was synthesized at 70oC for 3h of aging time (Ni_pH 12_3h_70oC), was the best-performing metal oxide. Compared with nickel electrodes, the NiCoZn electrode exhibited high OER (oxygen evolution reaction) and ORR (oxygen reduction reaction) activities because the combination of cobalt and zinc oxides with nickel provides excellent electrolyte access capability and promotes effective ion transfer through the active material. The NiZn battery with NiCoZn electrode showed a high capacity of 192.7 mAh gactive−1 at 10 mA cm−2 and cycling durability (after cycling at 10 mA cm−2 for 70 cycles). Benefiting from the excellent interaction between Ni, Co, and Zn, NiCoZn exhibited high onset potential and current density, suggesting that the NiCoZn electrode is a promising candidate as a high-performance configuration for Ni-based electrodes in NiZn batteries.

Hydrothermally designed Ag-modified TiO2 heterogeneous nanocatalysts for efficient hydrogen evolution by photo/electro/photoelectro-chemical water splitting

One compelling goal of carbon-neutrality is to advance sustainable energy applications through advanced functional nanomaterials for achieving remarkable performance in energy conversion processes, especially in green H2energy. Here, Ag-modified TiO2nanostructures with highly specific exposed surface sites have been fabricated hydrothermally, elucidating its prominence towards photocatalytic, and photo/-electrocatalytic H2production. Further, the as-synthesized nanomaterials were investigated by XRD, electron microscopy (SEM/EDAX/TEM/HRTEM), ICP-MS, PL, Raman, UV-visible DRS, and BET surface area studies. The enhanced activity was established due to the exceptional optoelectronic properties and highly exposed active sites of the Ag-modified TiO2nanocatalysts. The photocatalytic activity of 2.5% Ag-doped TiO2photocatalyst demonstrated the highest hydrogen evolution, measuring 15.66 mmolgcat-1with 17.33% apparent quantum yield. Moreover, for photo-electrolysis, 1% and 2.5% Ag-doped TiO2nanocatalysts exhibited significantly improved activity with Tafel slopes of 162.49, 87.56 mV dec-1and onset potentials of 0.77 V (at 1.55 mA cm-2), -0.96 V (at 10 mA cm-2) for oxygen evolution reaction and hydrogen evolution reaction in alkaline and acidic conditions. Experiments indicated that incorporation of Ag ions in TiO2boosted the H2evolution due to the extraordinary surface properties and the presence of defect-sides /oxygen vacancies.

A Dinuclear Nickel Complex for Electrocatalytic Nitrite Reduction.

While many mononuclear complexes for electrocatalytic NOx- reduction have been reported, there are few examples of dinuclear electrocatalysts. Here, we report on the electroreduction of NO2- by the dinuclear complex [Ni2(tpmc)(NO3)2]2+ (tpmc = 1,4,8,11-tetrakis-(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane) and a mononuclear analogue [Ni(cyclam)]2+ (cyclam = 1,4,8,11-tetraazacyclotetradecane). Notably, the presence of the second metal ion in [Ni2(tpmc)(NO3)2]2+ shifts the onset of catalysis anodically by ca. 0.3 V compared to [Ni(cyclam)]2+, while maintaining a similar electrocatalytic rate and Faradaic efficiency. Both complexes produce NH4+ as the primary reduction product. Interestingly, in some respects, Ni2+(aq) is a better electrocatalyst for NO2- than [Ni(cyclam)]2+, with faster electrocatalysis occurring at a more anodic onset potential, although the Faradaic efficiency for NH4+ is lower.

One-Component Catalytic Electrodes from Metal-Organic Frameworks Covalently Linked to an Anion Exchange Ionomer.

Anion-conducting organic-inorganic polymers (OIPs), constructed using metal-organic framework (MOF)-like structures with non-toxic, non-rare catalytic metals (Fe3+, Zr4+), have been developed. The incorporation of MOF-like structures imparts porosity to the polymers, classifying them as porous organic polymers (POPs). The combination between catalytic activity, ion conduction, and porosity allows the material to act as one-component catalytic electrodes. A high catalytic activity is expected since the entire surface area contributes to electrocatalysis, rather than being restricted to triple-phase boundaries. The synthesis involved anchoring a synthon onto a commercial polymer, assembling organo-metallic moieties, and functionalizing with quaternary ammonium (QA) groups. Two hybrid materials, Zr-POP-QA and Fe-POP-QA, were thoroughly characterized by NMR, FTIR, XPS, BET surface area (≈200 m2/g), and TGA. The resulting electrodes demonstrated a high electrochemically active surface area and a high efficiency for the oxygen reduction reaction (ORR), a critical process for energy storage and conversion technologies. The performance was characterized by a 4-electron reduction pathway, a high onset potential (≈0.9 V vs. RHE), and a low Tafel slope (≈0.06 V). We attribute this efficiency to the high active surface area, which results from the simultaneous presence of catalytic transition metal ions (Zr or Fe) and ion conducting groups.

Influence of Water Content on Electrochemical CO2 Reduction in Acetonitrile Solution on Cu Electrodes

AbstractThe electrochemical reduction of CO₂ (CO₂RR) on copper electrodes in acetonitrile (MeCN) solutions offers a promising route for converting CO₂ into valuable products but competes with the hydrogen evolution reaction (HER). This study systematically explores the impact of varying water content in MeCN on the selectivity and efficiency of CO₂RR and HER. Cyclic voltammetry shows that increasing water content shifts onset potentials and Tafel slopes, indicating changes in reaction mechanisms and rate‐determining steps. In dry MeCN, CO₂RR predominates due to high CO₂ solubility and limited proton availability, but as water content increases, HER kinetics improve, eventually dominating the reaction at higher water concentrations. In situ FTIR spectroscopy and molecular dynamics simulations reveal that water preferentially adsorbs onto the copper electrode surface, enhancing stabilization of reaction intermediates and facilitating HER. These findings provide critical insights into optimizing electrochemical systems for selective CO₂ reduction by controlling water content, offering a pathway for improved electrocatalytic performance.

Activation of Semiconductor/Electrocatalyst/Electrolyte Interfaces Through Ligand Engineering for Boosting Photoelectrochemical Water Splitting

AbstractThe loading of transition‐metal oxyhydroxide (TMOH) on semiconductor (SC) has been recognized as a promising approach for promoting photoelectrochemical (PEC) water splitting. Nonetheless, major challenges such as substantial carrier recombination and slow surface water oxidation continue to hinder the achievement of desirable PEC performance. This study proposes a feasible ligand engineering strategy to simultaneously boost charge separation and surface catalytic kinetics through coordinating 2‐methylimidazole (2‐MI) within a SC/TMOH system. In situ ultraviolet/visible spectroelectrochemistry (UV/vis‐SEC) and density functional theory (DFT) calculations show that the coordination of the 2‐MI ligand influences SC/TMOH and TMOH/electrolyte interfaces, notably enhancing the dynamics of hole transfer while simultaneously reducing the adsorption of oxygen‐containing intermediates. As anticipated, the BiVO4/FeNiOOH/2‐MI photoanode demonstrates an impressive photocurrent of 6.52 mA cm−2 at 1.23 VRHE, featuring excellent photostability and a low onset potential of 0.35 VRHE. Additionally, the 2‐MI molecule can be employed in the development of alternative configurations, such as BiVO4/FeNiOOH (soak)/2‐MI, to improve PEC efficiency. This work opens a new horizon in designing of desirable photoanodes for efficient and stable PEC water splitting.

Plasma Modification of Technical Carbon with Nitrogen and Sulfur-Containing Functional Groups for Application in Catalytic Systems

This study presents an effective plasma treatment method for doping technical carbon by nitrogen- and sulfur-containing functional groups. Nitrogen incorporation shifted the oxygen reduction reaction onset potential by 0.25 V and increased the limiting current by 1 mA cm−2, while sulfuration showed a more pronounced effect, with a 0.31 V shift in onset potential and an increase in the limiting current to 6.23 mA cm−2. These enhancements are attributed to the formation of additional active sites and improved surface properties. The proposed plasma-based approach is simple, scalable, and environmentally friendly, minimizing the use of hazardous reagents and eliminating the need for multistep processes. This method demonstrates the potential for industrial applications using commercially available raw materials such as technical carbon and to be extended to other carbon-based materials.

Incorporating Ordered Indium Sites into Rhodium for Ultra-Low Potential Electrocatalytic Conversion of Ethylene Glycol to Glycolic Acid.

The upcycling of polyethylene terephthalate (PET)-derived ethylene glycol (EG) to glycolic acid (GA, a biodegradable polymer monomer) via electrocatalysis not only produces valuable chemicals but also mitigates plastic pollution. However, the current reports for electrooxidation of EG-to-GA usually operate at reaction potentials of >1.0 V vs reversible hydrogen electrode (RHE), much higher than the theoretical potential (0.065 V vs RHE), resulting in substantial energy wastage. Herein, body-centered cubic RhIn intermetallic compounds (IMCs) anchored on carbon support (denoted as RhIn/C) are synthesized, which shows excellent performance for the EG-to-GA with an onset potential of only 0.35 V vs RHE, lower than the values reported in current literature. The catalyst also possesses satisfactory GA selectivity (85% at 0.65 V vs RHE). Experimental results combined with density functional theory calculations demonstrate that RhIn IMCs enhance the adsorption of EG and OH-, facilitating the generation of reactive oxygen species and thereby improving catalytic performance. RhIn/C also exhibits excellent electrocatalytic performance for hydrogen evolution reaction, ensuring that it can be used as a bifunctional catalyst in the two-electrode system for EG electrooxidation coupled with hydrogen production. This work opens new avenues for reducing the energy consumption of electrocatalytic upcycling of PET-derived EG and clean energy production.

Decoupling CO2 effects from electrochemistry: A mechanistic study of copper catalyst degradation.

Copper-based nanoparticles are key electrocatalysts for CO2 electrochemical reduction (CO2 ER) to liquid fuels and other value-added products. However, the copper catalyst can undergo rapid electrochemical corrosion, leading to a loss of catalyst material, fluctuations in the reaction conditions and increasing operational costs. We establish a mechanistic understanding of this detrimental process using in situ electrochemical electron microscopy and density functional theory (DFT). We find that copper corrosion can occur in the presence of CO2 in electroless conditions and before the onset potentials required for CO2 ER. The effects are isolated from pH changes resulting from dissolved CO2. Particles of corroded copper have oxidized surfaces, in contrast to copper surfaces exposed to CO2-free electrolytes. DFT calculations identify multiple routes by which CO2 can behave as a dissolution agent for copper and copper-oxide surfaces and suggest that formate-intermediates are a key driver of corrosion. This study highlights microenvironment-based factors that affect copper performance and degradation, facilitating strategies to inhibit and reverse copper degradation during CO2 ER.

Light Enhanced Water Dissociation in Bipolar Membranes

AbstractBipolar membrane (BPM) integration can allow robust and abundant materials to be implemented into energy conversion frameworks and purification pathways vital for the development of clean technologies. However, large membrane voltages associated with water dissociation (WD) have hampered widespread adoption. This work investigates an alternative method to reduce the overvoltage associated with WD operation by illuminating the BPM interface in the presence of nanoparticulate catalyst layers that exhibit plasmonic character. The plasmonic character of the catalyst enhanced the field locally near the active catalyst site, lowering the resistance associated with WD as well as the onset potential for WD. Optimal catalyst loadings allowed a balance of light absorption, catalyst activity, and field utilization. Composites of known WD catalysts that exhibited minimal light activity with a plasmonic and WD active material exhibited improvements in the WD resistance and overvoltage of up to 20 % upon irradiation. This proof‐of‐concept work introduces a new paradigm for altering WD activity in BPMs, where the optical activity of WD catalysts can provide further tunability towards efficient WD and alternative energy conversion frameworks.

The Ratio of sp2 and sp3 Hybridized Carbon Determines the Performance of Carbon‐based Catalysts in H2O2 Electrosynthesis from O2

AbstractIntroducing oxygen‐ or carbon‐containing functional groups is a widely adopted strategy to optimize the performance of carbon‐based catalysts for the two‐electron oxygen reduction reaction (2 e− ORR). Nevertheless, the specific contributions of these functional groups to enhance activity and selectivity are not well‐defined and continue under debate. In this study, we systematically modified carbon materials by controlling the contents of oxygen functional groups (OFGs) and carbon functional groups (CFGs). Surface compositions were accurately quantified using X‐ray photoelectron spectroscopy, and 2 e− ORR performance was evaluated using a rotating ring‐disk electrode (RRDE) in 0.1 M KOH. Through reliable statistical analyses, including partial least squares regression and linear regression, we explored the correlations between the surface compositional features – specifically the ratios of OFGs, CFGs, and sp2/sp3 hybridized carbon – and the catalytic performance metrics such as onset potential and H2O2 selectivity. Our findings challenge existing paradigms by demonstrating that the sp2/sp3 ratio is a critical factor in determining catalytic selectivity and a certain correlate with the 2 e− ORR onset potential. By tuning this ratio, we achieved nearly 100 % H2O2 selectivity within 0.4–0.6 V vs. RHE, and onset potential approached the thermodynamic potential (0.766 V vs. RHE for the O2/HO2‐ process), pointing a new direction in designing and developing advanced electrocatalysts for sustainable H2O2 synthesis.

Water Oxidation Electrocatalysis in Acidic Media with Fe-Containing POMs/Carbon Composites.

Iron-based catalysts are very appealing in terms of applications due to the low cost of Fe and to its abundance in the Earth's crust. In the field of water oxidation, unfortunately, iron oxides cannot match the activity of Co or Ni oxides, much less than the activity of noble metal oxides (IrO2). The activity of transition metals to promote the oxygen evolution reaction (OER) can be tuned and enhanced by their incorporation into polyoxometalate frameworks (POMs). In comparison with metal oxides, POMs offer a controlled, discrete structure and a tailor-made environment. Fe-POMs still show a low OER activity in neutral or basic media when compared to Co-POMs. When moving to highly acidic media, we have found an unexpected electrochemical response in carbon paste electrodes containing salts of the [Fe4III(H2O)2(PW9O34)2]6- (Fe4) polyanion. In oxidative conditions, these electrodes showed lower onset potentials and higher current densities than their Co-based analogues, contrary to computational expectations. Careful analyses have shown the excellent stability of the Fe4 in these pH < 1 conditions, but a poor selectivity. CO2 is the dominant product, in addition to O2. The capability of Fe4 to oxidize amorphous carbon under acidic conditions appears to be unique since it is not found in Fe oxides or simple Fe salts. Thus, Fe-POMs, in acidic conditions, are still modest OER catalysts, but exhibit a unique performance when electrochemically oxidizing carbon.

Modulating the Coordination Structure of Dual‐Atom Nickel Sites for Enlarging CO2 Electroreduction Potential Window

AbstractCO2 electroreduction (CO2ER) is a promising way to change CO2 into useful CO. However, high CO selectivity can only be realized in a narrow potential range, which largely limits its practical availability. Herein, the potential range for efficient CO2‐to‐CO conversion is effectively enlarged by developing dual‐atom Ni sites with surrounding uncoordinated N dopants dispersed in carbon nanotube substrate. This catalyst is synthesized through a novel precursor gas diffusion strategy to manipulate the coordination structures of atomic Ni. Remarkably, the dual‐atom catalyst exhibits a CO Faradaic efficiency above 92% in an ultra‐wide potential window from a low onset potential of −0.25 to −1.4 V (vs RHE), much superior to those state‐of‐the‐art atomic catalysts. Mechanistically, the unique dual‐atom Ni sites with uncoordinated graphitic N dopants can thermodynamically promote CO2‐to‐CO process via stabilizing the key *COOH intermediate, while simultaneously suppressing the parasitic hydrogen evolution. The findings reveal the correlation between the tailored coordination structures and CO2ER performance, so as to further guide the design of atomically dispersed catalysts for CO2ER process.