Durable Electrocatalysts Research Articles

Anion-rich Ir-doped CoOx for boosting oxygen evolution reaction in water electrolysis

Owing to the sluggish kinetics of oxygen evolution reaction (OER) in electrochemical water electrolysis process, efficient and durable OER electrocatalysts are crucially needed. However, it is a great challenge to improve the comprehensive performance of OER electrocatalysts by utilizing various synergistic methodologies. To solve these issues, herein, Ir-doped Co-based compounds with regulated anions were synthesized using a coprecipitation method as the electrodes for boosting the OERs. Doping with Ir atoms modified the coordination environments and electronic structures of the CoOx-CO32- lattice, and the generated Co3+ species promoted the generation of active species for the OER. It is worthwhile noting that a hybrid crystalline/amorphous IrCoOx-CO32- compound was obtained with an Ir content of 10.09 wt.% and a large amount of Co3+, and demonstrated excellent electrocatalytic OER performance. The overpotential required for the developed IrCoOx-CO32- to achieve 10 mA cm-2 was as low as 207 mV with a very low Tafel slope of 61.7 mV dec-1, which is better than the commercial IrO2. Furthermore, anions created in the IrCoOx significantly promoted the OER, and their effects were decreased in the order of CO32- > PO43- > OH-. This work clarifies the synergistic mechanism of cations and anions on the electrocatalytic OER performance of Co-based compounds, providing new insights for designs of high-performance OER electrocatalysts for water electrolysis.

Dynamic Confinement via Core‐Shell Built‐In Electric Field Achieves Sustainable High‐Current PEMWE

Abstract Developing efficient and durable bifunctional electrocatalysts for the acidic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is crucial for cost‐effective green hydrogen production. Although ruthenium (Ru) is widely recognized as a low‐cost alternative to iridium, their practical application is hindered by sluggish kinetics and dissolution. To address these limitations, a dynamic confinement strategy is developed through a novel core‐shell built‐in electric field (BIEF) to enhance both catalytic stability and activity of Ru‐based catalysts in acidic environments. The constructed Co3O4@RuO2 catalyst exhibits an OER overpotential of 189 mV and a HER overpotential of 55 mV at 10 mA cm−2. When integrated into a proton exchange membrane water electrolysis (PEMWE) system, it requires only 1.68 V to reach 1000 mA cm−2 and maintains stable operation for 400 h with a degradation rate of only 14.5 µV h−1. Experimental and theoretical results reveal that Co3O4 acts as an invisible protective shield to facilitate proton consumption at the catalyst surface and mitigate the electron depletion at the Ru site, thus preventing the over‐oxidation and dissolution of Ru. Furthermore, the enriched active sites and reduced adsorption energy of intermediates significantly boost the catalytic performance, making this catalyst highly promising for hydrogen production applications.

Time Tailoring NiFe2O4/Fe-NiS/Ni3S2 Heterocatalyst for Industrial-Scale Seawater Splitting.

Water electrolysis is a promising approach for hydrogen production. However, achieving cost-effective and durable electrocatalysts at large current densities for seawater splitting remains a significant challenge. This study synthesized a NiFe2O4/Fe-NiS/Ni3S2 heterostructure on nickel foam (NF) via a simple solvothermal method with varying reaction times. The NiFe2O4/Fe-NiS/Ni3S2/NF-12h catalyst requires overpotentials of 398 mV for the hydrogen evolution reaction (HER) and 373 mV for the oxygen evolution reaction (OER) to achieve a current density of 1000 mA cm-2 in an alkaline seawater medium. Notably, the NiFe2O4/Fe-NiS/Ni3S2/NF-12h (+,-) electrolyzer achieved a cell voltage of 1.92 V at 500 mA cm-2 and exhibited remarkable stability, maintaining its performance for more than 100 h at 500 mA cm-2 in an alkaline seawater electrolyte. These findings highlight the critical role of the reaction time in optimizing the morphologies of catalysts. Meanwhile, the synergistic effect of iron doping and interface interaction enhanced the electrocatalytic activity of NiFe2O4/Fe-NiS/Ni3S2. This work provides a practical strategy for designing high-performance electrocatalysts suitable for industrial-scale seawater electrolysis.

Induced charge regulation of rationally designed multisite synergism of high-entropy alloy-oxy-hydroxides as highly active durable multifunctional electrocatalysts

Induced charge regulation of rationally designed multisite synergism of high-entropy alloy-oxy-hydroxides as highly active durable multifunctional electrocatalysts

Exploration of vanadium-modified nickel selenide (NiV2Se4) bifunctional robust and durable electrocatalyst for alkaline OER and HER

Exploration of vanadium-modified nickel selenide (NiV2Se4) bifunctional robust and durable electrocatalyst for alkaline OER and HER

Amorphous NiFeCo Oxyhydroxide as a High‐Performance Electrocatalyst for Alkaline Oxygen Evolution Reaction

Abstract Developing efficient and durable electrocatalysts for the oxygen evolution reaction (OER) is critical for advancing water electrolysis technologies. Herein, we report the synthesis of amorphous Co/Mo‐alloyed NiFe oxyhydroxides (NiFeCo and NiFeMo) via a sol–gel method. Compared to NiFeMo, the NiFeCo catalyst demonstrates higher OER activity and stability in alkaline media. It achieves a low overpotential of 234 mV at 10 mA/cm2 and a Tafel slope of 72 mV/dec. It maintains stable performance for over 100 h in both three‐electrode and anion exchange membrane water electrolyzer (AEMWE) configurations. Co alloying induces changes in oxidation states, stabilizing high‐valent Ni/Fe species and enhancing charge transfer kinetics, whereas the amorphous structure ensures structural adaptability under prolonged operation. Postoperation characterization reveals retained amorphous integrity despite particle agglomeration, highlighting the synergy between dynamic structural flexibility and electronic optimization. This work provides a promising pathway for designing nonprecious metal‐based OER catalysts for industrial water electrolysis applications.

Interface-Engineered RuP2/Mn2P2O7 Heterojunction on N/P Co-Doped Carbon for High-Performance Alkaline Hydrogen Evolution.

Developing efficient and durable electrocatalysts for the alkaline hydrogen evolution reaction (HER) is crucial for sustainable hydrogen production. Herein, we report a novel RuP2/Mn2P2O7 heterojunction anchored on a three-dimensional nitrogen and phosphorus co-doped porous carbon (RuP2/Mn2P2O7/NPC) framework as a high-performance HER catalyst, synthesized via a controlled pyrolysis-phosphidation strategy. The heterostructure achieves uniform dispersion of ultrafine RuP2/Mn2P2O7 heterojunctions with well-defined interfaces. Furthermore, phosphorus doping restructures the electronic configuration of Mn and Ru species at the RuP2/Mn2P2O7 heterointerface, enabling enhanced catalytic activity through the accelerated electron transfer and kinetics of the HER. This RuP2/Mn2P2O7/NPC catalyst exhibits exceptional HER activity with 1 M KOH, requiring only 69 mV of overpotential to deliver 10 mA·cm-2 and displaying a small Tafel slope of 69 mV·dec-1, rivaling commercial 20% Pt/C. Stability tests reveal negligible activity loss over 48 h, underscoring the robustness of the heterostructure. The RuP2/Mn2P2O7 heterojunction demonstrates markedly reduced overpotentials for the electrochemical HER process, highlighting its enhanced catalytic efficiency and improved cost-effectiveness compared to the conventional catalytic systems. This work establishes a strategy for designing a transition metal phosphide heterostructure through interfacial electronic modulation, offering broad implications for energy conversion technologies.

Iron modulated high entropy engineering boosting alkaline oxygen evolution.

Iron modulated high entropy engineering boosting alkaline oxygen evolution.

N,P-Coordinated Breaking Local Charge Symmetry of Fe Single Atoms for Highly Efficient Electrocatalytic Oxygen Reduction.

Efficient and durable electrocatalysts for the oxygen reduction reaction (ORR) are pivotal in energy conversion and storage systems, particularly in alkaline fuel cells and metal-air batteries. Atomically dispersed Fe-NC electrocatalysts are a promising alternative to platinum group metal (PGM) catalysts. However, their catalytic activity and stability must be significantly improved. In this study, we introduce P atoms to disrupt the local charge symmetry of the Fe-N4 configuration, thereby reducing the ORR energy barrier and boosting the electrocatalytic performance. The resulting atomically dispersed Fe catalyst (FeN3PO) exhibits exceptional ORR activity under alkaline conditions, achieving a half-wave potential of 0.91 V, which is 57 mV higher than that of the Pt/C catalyst. Furthermore, it demonstrated negligible performance degradation during stability testing. When employed as the cathode catalyst in rechargeable zinc-air batteries, FeN3PO delivers a power density that far exceeds that of the 20% Pt/C catalyst, reaching 257 mW cm-2. Density functional theory calculations reveal that doping with P optimizes the Fe 3d orbitals and accelerates the rate-determining step, thereby significantly enhancing the catalytic activity. This research provides novel insights into the optimization of non-precious metal single-atom ORR catalysts.

Hierarchical nickel phosphide-MXene nanosheets composite as durable electrocatalyst for electrochemical hydrogen production via water-splitting

In this study, a thoroughly durable hydrogen evolution reaction (HER) electrocatalyst, nickel phosphide (NiP2), was grown on conductive Ti3C2MXenes synthesized via a non-HF hydrothermal route. This approach utilizes MXenes as both a support and promoter to accelerate charge transfer, enabling efficient HER at a very low overpotential. A hydrothermal strategy was developed for thein-situgrowth of NiP2microflowers on Ti3C2sheets at low temperature. The improved delamination of MXenes achieved through this novel method facilitates the growth and intercalation of active electrocatalysts betwixt the 2d MXene sheets. High electrical conductivity of MXenes, coupled with the strong interfacial coupling between MXene sheets and NiP2, significantly enhances the HER performance compared to pristine MXene or NiP2alone. The as-prepared MXene-NiP2composite demonstrates excellent stability and current density, achieving an overpotential of ∼70 mV, which is comparable to state-of-the-art Pt-based electrocatalysts. This strategy for constructing MXene-based heterostructures demonstrates the NiP2/MXene composite as an outstanding candidate for electrolytic hydrogen production. Additionally, MXenes are highlighted as ideal conductive supports for the growth of other electrocatalysts, paving the way for the development of heterostructured materials with enhanced stability in various media, making the water-splitting process more cost-effective.

Improved Electrochemical Performance of Bifunctional Electrocatalysts Based on Prussian Blue Analogues for Zn-Air Batteries

Prussian Blue Analogues (PBAs) have emerged as promising materials for energy storage and conversion applications. In this study, we synthesized PBA derivatives doped with Mn, Co, Ni, Zn, and Cu, supported on nitrogen-doped carbon aerogels (NCA), and evaluated their potential as bifunctional electrocatalysts for rechargeable zinc-air batteries. Structural and morphological analyses revealed the homogeneous dispersion of metal species in the NCA framework, ensuring effective active site exposure. Electrochemical characterizations demonstrated that MnCoNiZnCuPBA@NCA exhibited superior oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) performance, as evidenced by its high current density, low overpotential, and excellent Tafel slope. Furthermore, MnCoNiZnCuPBA@NCA achieved the highest discharge capacity (601.80 mAh.g-1) and energy density (322.67 mWh.g-1) among the materials studied, along with remarkable cycling stability. These findings underscore the potential of MnCoNiZnCuPBA@NCA as an efficient and durable bifunctional electrocatalyst for next-generation zinc-air batteries.

Understanding Methanol Electro-Oxidation Pathways on Nd-Based Metal Oxides via DFT and Electrochemical Studies.

In this study, we report for the first time the electrochemical performance of Nd-based metal oxides (NdNiO (NNO), NdCuO (NCO), and NdZnO (NZO)) as electrocatalysts for methanol electro-oxidation. Results show that NCO exhibits superior electrocatalytic performance with a low onset potential of 0.97 V versus reversible hydrogen electrode (RHE) and excellent resistance to CO poisoning. Electrochemical impedance spectroscopy (EIS) revealed a low charge transfer resistance (Rct) of 1.30 Ω, indicating efficient electron transfer kinetics. The calculated mass activity (MA) of NCO was 1.68 A/mg, surpassing various reported Pt-based catalysts, such as Pt62Ru35/C (0.47 A/mg), Pt62Ru18Ni20-O/C (0.30 A/mg), and comparable to Pt62Ru18Ni20/C (1.91 A/mg). The density functional theory (DFT) calculation shows that NCO facilitates methanol oxidation through the CHO* intermediate, indicating efficient CO oxidation and CO2 release. The synergy between Cu 3d and O 2p orbitals plays a crucial role in enhancing the electrocatalytic performance. These findings highlight NCO as a promising and durable electrocatalyst in energy conversion technologies.

Single-Atom Mediated d-Band Engineering of Platinum Nanocatalysts for High-Efficiency Acidic Hydrogen Evolution.

The rational construction of single-atom-mediated Pt catalysts with optimized electronic structures and robust stability remains a grand challenge for hydrogen evolution reaction (HER). Herein, spatial confinement coupled with a d-band engineering strategy is pioneered to fabricate cobalt single-atom coordinated Pt nanocatalysts (Pt@Co-SAs/NC), achieving exceptional HER activity with ultralow Pt loading (0.94 wt%). The Pt@Co-SAs/NC exhibits an overpotential of 15 mV at 10 mA cm-2 (η10) and 21.8-fold enhanced mass activity at 20 mV versus commercial Pt/C, surpassing most reported Pt-based systems. Synchrotron X-ray absorption spectroscopy and theoretical studies reveal that the atomically dispersed CoN4 sites adjacent to Pt NPs serve as electronic modulators, inducing a 0.36 eV downshift of the Pt d-band center through interfacial charge redistribution. This electronic engineering weakens hydrogen adsorption strength (ΔGH* = -0.17 eV) while accelerating H2 desorption kinetics. Furthermore, the CoN4-anchored carbon matrix suppresses nanoparticle aggregation and ensures exceptional durability through strong metal-support interactions, maintaining 94.2% activity after 130 h operation. This work establishes an atomic-level electronic modulation paradigm for designing highly efficient, cost-effective, and durable electrocatalysts.

Nickel-Induced Activation of Iron Foam for the Oxygen-Evolution Reaction: A Multimodal Study of Structure and Dynamics.

Iron/nickel (hydr)oxides are widely recognized as efficient catalysts for the oxygen-evolution reaction (OER) in alkaline media. In this study, the effect of Ni on Fe foam toward OER activity is investigated. Treatment with nickel(II) nitrate induces the emergence of oxidation and reduction peaks, whose intensity and position are modulated by the nickel concentration on the iron foam surface. Remarkably, the OER onset potential exhibits a 240 mV reduction in overpotential upon the incorporation of nickel ions. In-situ Raman spectroscopy reveals the formation of γ-NiO(OH) during OER. Although substantial Fe ions are incorporated into the nickel (hydr)oxide matrix, reduced OER activity and a negative potential shift in the Ni(II)/(III) peak suggest Fe leaching during OER. Based on our findings, we propose a structure featuring multiple active sites, including nickel-doped iron hydroxide, iron oxide, nickel hydroxide, and mixed nickel/iron hydroxides with varying stoichiometries. This work highlights nickel-induced activation of iron foam to enhance OER performance, offering valuable insights for designing advanced, cost-effective, and durable electrocatalysts for applications such as water splitting and renewable energy storage systems.

Synergistically Regulating the Electronic Structure and Stabilizing the Lattice Oxygen of Spinel Cobalt Oxide by Mo and Pr Dual Doping to Enhance Acidic Oxygen Evolution Performance.

Developing active and durable nonprecious metal-based electrocatalysts for the acidic oxygen evolution reaction (OER) poses a significant challenge. Cobalt (Co)-based spinel oxides are promising non-noble metal-based acidic OER electrocatalysts, but their practical applications are hindered by inadequate activity and durability due to their nonideal electronic structure and easily leached Co species. Here, a dual-cation doping strategy based on molybdenum (Mo) and praseodymium (Pr) is developed to highly enhance the acidic OER activity and stability of Co3O4 spinel. Combining experimental and theoretical studies, it is revealed that Mo and Pr codoping can cooperatively modulate the electronic properties of Co3O4 and optimize the adsorption/desorption energies of reaction intermediates. Meanwhile, it can effectively suppress the formation of oxygen vacancies by enhancing Co-O bonds and avoid the dissolution of Co species in Co3O4 under acidic conditions. More importantly, codoping Co3O4 with Mo and Pr induces a thermodynamically favorable OER reaction pathway following the oxide path mechanism (OPM), resulting in a reduced reaction energy barrier for the rate-determining step. As a result, the Mo- and Pr-codoped Co3O4 (MoPr-Co3O4) exhibits enhanced OER performance, with a low overpotential of 254 mV at 10 mA cm-2 and good long-term stability of 120 h in an acidic medium.

Advanced Fe Electrocatalysts: Unlocking Sustainable, Selective, and Durable Seawater Electrolysis

Abstract Seawater electrolysis (SWE) serves as a renewable alternative, significantly lowering the costs of electrolyzer technologies by eliminating the need for supplementary water purification operations, hence facilitating marine offshore H2 generation and providing pure drinking water. Nonetheless, the intricate composition of seawater and the challenges associated with commercial SWE are significant, including local pH variations, solid impurities and precipitates, and the competition between the chlorine evolution reaction (CER) and oxygen evolution reaction (OER). To reshape the energy landscape and achieve carbon neutrality, the development of cost‐efficient electrocatalysts for SWE with adjustable electrocatalytic activity, enhanced OER selectivity, and sustained stability under elevated current densities is a crucial consideration and pragmatic option. This review systematically elucidates the principles and mechanisms of SWE, analyzes corrosion resistance strategies, and identifies difficulties related to activity and durability to enhance comprehensive research and practical application of Fe‐based electrocatalysts. It critically examines diverse contemporary methodologies for tailoring advanced Fe nanomaterials and summarizes the latest developments in various electrocatalysts for hydrogen evolution reaction (HER), OER in seawater, and overall seawater splitting (OSWS), supported by significant studies from recent literature. Furthermore, current challenges, opportunities, and distinctive insights for developing efficient and durable electrocatalysts and integrated seawater electrolyzers are well emphasized.

Microwave‐Assisted Synthesis of Nickel Sulfide/Iron Sulfide (NiS2/Fe7S8) Rods for Oxygen Evolution Reaction

Generation of hydrogen fuel from renewable sources like water via electrolysis is an effective process to produce it. For this process an efficient, inexpensive, and durable electrocatalyst is required for splitting of water molecules. Herein, a rod‐shaped nickel sulfide/iron sulfide (NiS2/Fe7S8) electrocatalyst is fabricated for the water splitting reaction by the microwave method. NiS2/Fe7S8 exhibits a very low overpotential of 250 and 300 mV at current densities of 25 mA cm−2 (η25) and 40 mA cm−2 (η40), respectively, and a Tafel slope value of 26 mV dec−1 for oxygen evolution reaction in a basic electrolyte. It shows electrochemical stability of 45 h with low impedance and high electrochemical surface area.

Porous CeO2/CuO Heterostructure for Efficient Hydrogen Evolution Reaction in an Acidic Medium.

A composite electrocatalyst CeO2/CuO is fabricated for the hydrogen evolution reaction (HER) via a simple, facile, one-step hydrothermal method, using F-127 as a template and structure directing agent. The prepared composite CeO2/CuO shows top-notch HER activities with a small overpotential of 98 mV at 10 mA cm-2 and just 160 mV overpotential to attain a current density of 50 mA cm-2 with good stability for 20 h in an acidic medium. The enhanced catalytic activities of CeO2/CuO nanocomposite are attributed to their synergetic interface interaction, which lead to improved conductivity, reactive sites, and oxygen vacancies in their lattices. This study aims to advance the development of earth-abundant transition metal oxides-based electrocatalysts as economical, durable, and efficient HER electrocatalysts to replace noble metal-based materials in the future.

Functional Engineering Iron Single-Atom Sites on MOF Supports for Enhanced Electrochemical Water Splitting.

The precise control of the local environment, electronic configuration, and electrocatalytic performance of transition metal single-atom sites on nitrogen-carbon supports (MSA-N-C) is essential for electrolytic hydrogen production due to the inherent rigidity of the catalytic active centers. A highly catalytically active and durable bifunctional metal single-atom site on nitrogen-carbon supports (MSA-N─C; M═Fe, Co, and Cu) is demonstrated using a porphyrin-based metal-organic framework (MOF) strategy. Engineered iron single-atom sites on nitrogen-carbon support (FeSA-N─C) demonstrate remarkable electrocatalytic performance for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) in an alkaline electrolyte. This is achieved through the optimization of the coordination structure and a large volume of active sites, which advance the intrinsic catalytic activity. The FeSA-N─C catalyst exhibits low overpotentials of ≈288.0mV for the OER and 206.0mV for the HER at roughly ≈10mA cm-2 in 1.0m KOH. This improved catalytic performance is due to enhanced Fe─N─C coordination, which promotes the formation and activation of the vital O═Fe═O intermediate. This, in turn, improves the electrocatalytic properties by reducing the energy barriers of the intermediates and products involved.This strategy demonstrates the enrichment of the micro-environment Fe-N4 with tunable flexibility, aiding in the rational design of durable electrocatalysts at the atomic scale.

Interfacial Engineering and Structural Modulation of RuO2-Based Catalysts for Highly Active and Durable Oxygen Evolution Reaction in Acidic Environment.

Developing highly active and durable catalysts for the oxygen evolution reaction (OER) under acidic conditions is key to commercializing green hydrogen production via water splitting. Here, we fabricated a cobalt oxide (Co3O4)-synergized nickel-doped ruthenium oxide (Ni-RuO2) heterojunction on reduced graphene oxide (Co3O4/Ni-RuO2/rGO) as an efficient and durable OER electrocatalyst in acidic electrolytes. The interface of Co3O4/Ni-RuO2 heterojunction and doping of Ni into RuO2, as well as their effect on electronic structure, were examined by advanced characterizations. With only 1.36 wt% RuO2, the Co3O4/Ni-RuO2/rGO heterojunction revealed an ultra-low overpotential of 195 and 305mV at 10 and 100mA cm-2, respectively. Moreover, the catalyst's performance was well maintained after operating for 100h at 500mA cm-2, suggesting great promise for practical applications. Density functional theory calculations and in situ Raman analysis indicate that both the heterojunction structure and Ni doping play crucial roles in enhancing the OER activity and durability. This study provides a promising avenue for developing cost-effective electrocatalysts with superior activity and stability for advanced energy conversion.