The widespread deployment of Pt-based catalysts in electrochemical energy systems is limited by their scarcity and poor durability. To overcome these challenges, we developed a series of cobalt-nitrogen-carbon (Co(x)NC@PPy) aerogel catalysts using a combined freeze-drying and pyrolysis strategy. This method yielded homogeneous, hierarchically structured materials with a high specific surface area of 279.17 m2 g- 1. Systematic variation of cobalt chloride precursor loading revealed that 150 mg provided optimal performance. The Co(150)NC@PPy catalyst exhibited uniform cobalt dispersion and delivered excellent oxygen reduction reaction (ORR) activity in acidic media, achieving a half-wave potential of 0.7216 V approaching that of commercial Pt/C catalysts. Furthermore, it demonstrated a limiting current density of -4.68 mA cm- 2 and a Tafel slope of 45.22 mV dec-1, indicating favorable reaction kinetics. Upon extended durability testing over 30,000 cycles, The catalyst undergoes activation in the acidic electrolyte, where prolonged exposure enhances the wettability between the electrolyte and the catalyst. This improvement facilitates the adsorption of reactants and desorption of products, while also removing surface-adsorbed impurities or oxide layers, thereby enabling the catalyst to exhibit excellent durability.

Proton exchange membrane fuel cells are promising clean energy conversion devices, yet their widespread commercialization is hindered by high cost and insufficient stability of Pt catalysts. Herein, we propose a ternary PtCoCu alloy catalyst via the ammonia complex precipitation method. To address the issues of insufficient stability and high solubility of the binary Pt-Co alloy catalyst, a ternary system is constructed to reduce costs, enhance activity, and facilitate the large-scale application of fuel cells. The Cu-Co synergistic effect induces lattice contraction of Pt, thereby accelerating the ORR kinetics by modulating the surface strain. Theory calculations confirm that Pt3Co1Cu1 significantly lowers the energy barrier of the rate-determining step (*OOH→*O), reducing the overpotential by 1.73 V compared to binary Pt3Co2 (5.03 V). This enhancement is attributed to the electronic states of Pt being tuned closer to the Fermi level, optimizing the adsorption strength of intermediates. Experimentally, the Pt3Co1Cu1 catalyst shows high mass activity (270.5 mA/mgPt) and specific activity (0.183 mA/cmPt2), superior to that of Pt/C (201.77 mA/mgPt and 0.047 mA/cmPt2). Moreover, Pt3Co1Cu1 catalyst demonstrates exceptional durability, retaining significantly higher activity than Pt/C after 80000 cycles. Fuel cell tests indicate that the peak power density reaches 1263 mW/cm2, demonstrating excellent electrocatalytic performance and promising application potential. This study provides a valuable design methodology and theoretical insight for developing ternary alloy ORR catalysts in fuel cell applications.

Anion-exchange membrane water electrolysis (AEMWE) stands as a leading technology for producing hydrogen from intermittent renewable electricity. However, the development of cost-effective, durable non-noble metal catalysts remains a critical bottleneck hindering its large-scale deployment in alkaline environments. Herein, we tune the catalytic activity and reaction pathways of a model non-noble metal catalyst through oxygen vacancy engineering and elucidate the underlying structure-activity relationship. Experimental characterization and density functional theory (DFT) calculations reveal that the enhanced oxygen evolution reaction (OER) performance of the optimal sample originates from the pronounced local distortion of NiO octahedra induced by high-concentration oxygen vacancies. This structural distortion may induce a mechanistic transition from the conventional adsorbate evolution mechanism (AEM) to the oxygen-vacancy-mediated mechanism (OVSM). Within this OVSM framework, lattice oxygen is directly involved in O–O bond formation, thereby circumventing the inherent linear scaling relation constraints in the AEM. In practical AEMWE device testing at 60 °C and 1 M KOH, the electrolytic cell with NiO450 as the anode operated continuously for 100 h at an application-oriented current density of 1 A cm−2, with a voltage fluctuation of only 8.6 mV and negligible performance decay. This work highlights the pivotal role of oxygen vacancies in mediating the trade-offs among catalyst structure, intrinsic activity, and long-term stability, and offers valuable guidance for the rational design of highly robust non-noble nickel-based oxygen evolution reaction electrocatalysts.

Developing efficient and cost-effective oxygen reduction reaction (ORR) catalysts is crucial for advancing clean energy technologies. In this study, the 3D polypyrrole aerogel was synthesized using methyl orange as a soft template. The subsequent in situ spatially confined pyrolysis ensures the atomic dispersion of Co-Nx active sites while effectively suppressing metal agglomeration. The optimized CoNC-150 catalyst exhibited a high surface area (298.53m2/g) and well-distributed cobalt-coordinated active sites (Co-N4), significantly enhancing ORR performance. Electrochemical evaluations demonstrated an exceptional half-wave potential of 0.886V, closely approaching that of commercial 20 wt.% Pt/C (0.892V). The catalyst followed a four-electron transfer pathway, ensuring efficient ORR kinetics. Remarkably, this robust 3D monolithic architecture endows the catalyst with exceptional stability in alkaline media. Long-term durability tests over 40 000 cycles confirmed their remarkable stability, with only a 0.008V loss in half-wave potential, significantly lower than the 0.022V loss in Pt/C under similar conditions. The degraded CoNC-150 exhibited a half-wave potential of 0.878V, significantly outperforming Pt/C (0.870V). Kinetically, CoNC-150 exhibits a Tafel slope of 146.16 mV/dec, indicating favorable ORR dynamics. These results highlight the potential of CoNC-150 as a highly active and durable nonprecious metal catalyst (NPMC) for ORR applications. This study provides valuable insights into the rational design of transition metal-based electrocatalysts, offering a promising route toward scalable and sustainable energy conversion technologies.

High-loading (≥50 wt.%) anode catalysts for direct methanol fuel cells often suffer from severe metal agglomeration, which limits Pt utilization and long-term catalytic stability. In this work, highly dispersed PtRu/C catalysts with 50 wt.% metal loading were prepared using a staged strategy combining microwave-induced nucleation and oil-bath-controlled alloying growth. An ultrafine PtRu/C catalyst with an average particle size of ∼4.2 nm was obtained, exhibiting a methanol oxidation current density of 25.14 mA·cm−2, about 2.1 times that of the commercial JM-PtRu benchmark. Single-cell DMFC tests showed that Pt2Ru1/C achieved a peak power density of 31.63 mW·cm−2 and a Pt-mass-specific peak power density of 103 mW·mgPt−1. These results suggest that the dual-stage synthesis strategy improves Pt utilization by balancing high metal loading, PtRu alloying, and nanoparticle dispersion, providing a practical route for designing high-loading anode catalysts for DMFC applications.

Developing oxygen evolution reaction (OER) catalysts that combine high performance with cost-effectiveness is a critical challenge for advancing the commercialization of anion exchange membrane water electrolysis (AEMWE). Practical application is often hindered by issues such as poor batch reproducibility and low-cost efficiency. To address these limitations, this study proposes a morphology-engineering strategy centered on oxygen vacancy modulation. Using nickel cobaltite as a model system, this strategy employs a low-cost, low-alkalinity solution medium and a gradient annealing process to achieve an optimal combination of tailored morphology and controlled oxygen vacancy concentration. Experimental characterization and density functional theory (DFT) calculations reveal that an appropriate annealing temperature (400 degrees C) effectively constructs active coordination sites, facilitates the proton-coupled electron transfer process, and thereby significantly enhances the OER performance. The performance loss after continuous operation for 112 h in the AEMWE single-cell device is negligible, highlighting its excellent uniformity and stability. This work not only confirms the crucial role of the oxygen-vacancy-modulated morphology-engineering strategy in improving the OER performance of spinel oxides but also provides important insights and a technical pathway for designing highly active catalysts suitable for practical water electrolysis systems. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) (OER) (sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) (AEMWE) (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) (DFT) (sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic) (400 degrees C) (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)OER(sic)(sic).(sic)AEMWE(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)112 h(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)OER(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).

ABSTRACT Developing oxygen evolution reaction (OER) catalysts that combine high performance with cost‐effectiveness is a critical challenge for advancing the commercialization of anion exchange membrane water electrolysis (AEMWE). Practical application is often hindered by issues such as poor batch reproducibility and low‐cost efficiency. To address these limitations, this study proposes a morphology–engineering strategy centered on oxygen vacancy modulation. Using nickel cobaltite as a model system, this strategy employs a low‐cost, low‐alkalinity solution medium and a gradient annealing process to achieve an optimal combination of tailored morphology and controlled oxygen vacancy concentration. Experimental characterization and density functional theory (DFT) calculations reveal that an appropriate annealing temperature (400°C) effectively constructs active coordination sites, facilitates the proton‐coupled electron transfer process, and thereby significantly enhances the OER performance. The performance loss after continuous operation for 112 h in the AEMWE single‐cell device is negligible, highlighting its excellent uniformity and stability. This work not only confirms the crucial role of the oxygen‐vacancy‐modulated morphology–engineering strategy in improving the OER performance of spinel oxides but also provides important insights and a technical pathway for designing highly active catalysts suitable for practical water electrolysis systems.

Pt-based materials are widely recognized as the most effective and commonly used catalysts for the oxygen reduction reaction (ORR). However, their high cost and limited availability have spurred a significant search for alternative non-precious metal catalysts that offer both affordability and high performance. Carbon black is a particularly appealing precursor for producing cost-effective, high-performance catalysts due to its rich micropore structure and excellent conductivity, which facilitate electron transfer when used as an ORR catalyst support. In this work, introduce a highly active ORR catalyst (C/D-Co) that integrates Co-N, pyridinic-N, graphitic-N, and Co4S3/Co nanoparticles. The C/D-Co catalyst exhibits impressive ORR electrocatalytic performance, with an onset potential of 0.79 V, a half-wave potential of 0.67 V, and a limiting current density of 6.76 mA cm-2 Additionally, studies conducted using rotating disk electrode experiments have revealed that the hydrogen peroxide yield and the number of electron transfers of the C/D-Co catalyst are comparable to those of a 20 wt% Pt catalyst, exhibiting excellent catalytic activity while significantly reducing costs. Density functional theory (DFT) calculations further demonstrate that the synergistic effect of nitrogen and sulfur dopants on the graphitized carbon surface enhances the modulation of electron density at the Co active center, thereby achieving superior oxygen reduction reaction (ORR) activity.

Abstract Nowadays, the depletion of non‐renewable energy sources has become a prominent issue, and environmental concerns such as air pollution stemming from vehicle emissions have reached a critical stage. In this manuscript, we introduce a novel approach for the fabrication of Pt/C catalysts on a large scale, utilizing a simple, rapid, and continuous pipeline microwave synthesis method. Moreover, we incorporate a heating treatment process in an N2−H2 (5 % H2) environment to enhance the activity and durability of the catalyst. The synthesized Pt/C‐400 catalyst demonstrates an impressive electrochemical active surface area of 103.2 m2/gpt and a mass‐specific activity of 315 mA/mg at a half‐wave potential of 0.9 V. Following 30000 cycles of Pt attenuation testing and 30000 cycles of carrier attenuation testing, the Pt/C‐400 catalyst exhibits a remarkable retention rate of 75 %. Furthermore, based on single‐cell testing, the Pt/C‐400 catalyst achieves a voltage of 0.606 V at a current density of 2000 mA/cm2, surpassing the performance of other Pt/C catalysts discussed in this article. This study presents an efficient and practical method for large‐scale synthesis of high‐performance and durable catalysts. The findings hold significant implications for the commercialization of Proton Exchange Membrane Fuel Cells and contribute to addressing the pressing need for sustainable energy solutions.

In methanol oxidation reaction (MOR), it is crucial for the catalyst that Pt particles uniformly cover the surface of the carrier and the Pt surface active sites can effectively remove the binding with CO. This article develops a simple and effective continuous microwave technology. Carbon loaded nano platinum was synthesized by rapidly and uniformly heating a ethylene glycol mixture containing carbon black (CB) H2PtCl6 using microwave radiation, with a Pt content of 49.5%. The experimental results indicate that platinum particles are uniformly loaded onto the carbon surface, with uniform shape and size, and an average particle size of 3.02 nm. And the Pt/C catalyst prepared by continuous microwave technology showed enhanced electrocatalytic activity (peak current density of 76.95 mA/cm2) in MOR after heating at appropriate temperature in N2 atmosphere, which exceeded the commercial catalyst TKK (47.07 mA/cm2) by 63.6%. And the catalyst's resistance to CO toxicity and durability; Higher than commercial Pt/C catalysts. Compared with traditional methods, continuous microwave technology exhibits higher energy utilization efficiency and faster reaction speed in the catalyst preparation process. This technology also has the ability to achieve continuous preparation, which is one of the effective technological approaches to achieve large-scale catalysts production.

To address the issue of poor long-term stability of catalysts in proton exchange membrane fuel cells (PEMFC), a dual heat treatment approach was employed to prepare Pt/C catalysts using pretreated carbon black as the carbon support. The Pt/C catalysts underwent both pre- and postheat treatments to enhance their performance. The test results demonstrated that the electrochemical active surface area (ECSA) of the Pt/CB300-700 catalyst only decreased by 4.4% after 30,000 cycles. Furthermore, when the Pt/CB300-500 catalyst was fabricated into a membrane electrode assembly (MEA) and subjected to single-cell performance testing, it exhibited a significantly higher potential of 0.648 V at a current density of 2000 mA/cm(2), compared to the commercial catalyst's 0.546 V. This dual heat treatment approach enables the preparation of highly stable and active Pt/C catalysts, providing valuable research insights and technical references for the production of high-performance oxygen reduction catalysts.

One of the most effective synthesis routes is the simple solution process, which is an inexpensive way to make single phase 2-Dimensional (2D) Tin Selenide (SnSe) nanosheets. X-ray diffraction (XRD), X-ray Photoelectron spectroscopy (XPS), and Field Emission Scanning Electron Microscope (FESEM) were used to confirm the structural and topographical investigations. 2D SnSe served for Oxygen Reduction Reaction (ORR) electrochemical performance in KOH solution. Later, 2D SnSe is annealed at 300, 400 and 500 & DEG;C later termed as SnSe-300, SnSe-400 and SnSe-500 respectively to investigate the electrochemical behavior of catalyst. As the temperature increases ORR performance improved. For the first time, 2-and 4-electron transfer pathway mechanism of SnSe catalysts is discussed. As enhancement in the performance of as prepared 2D SnSe catalysts ensured with various parameters like current density, electron charge transfer number and half-wave potential. SnSe-500 has a half-wave potential of -0.75 V, which is lower than other catalysts in this case. In addition, a current density of 4.50 mA/cm(2) was recorded, which is superior to other catalysts in this case.

Two-dimensional (2D) nanostructures are attractive candidates for electrocatalytic applications owing to their excellent mechanical flexibility and large exposed surfaces. In this work, we present ultra-thin 2D NiO porous nanosheets prepared by a simple, economical and green experimental method (hydrothermal, freeze-drying, and sintering) as efficient electrocatalysts for direct methanol fuel cell (DMFC) application. Benefiting from the ultra-thin 2D framework and porous nanostructure, the 550-NiO catalyst (annealed at 550 degrees C) exhibit higher current density (12.54mA cm(-2)) and faster charge transfer in the catalytic process, due to its abundant solid state redox couples (Ni2+/Ni3+ = 0.991), suitable oxygen defects and surface coverage of redox species (2.90 x 10(-7) mol cm(-2)). First-principles density functional theory calculations were employed to provide mechanistic insights into the methanol oxidation reaction over the NiO catalyst via methanol dehydrogenation to CO involving O-H and C-H bond scissions, and subsequently, CHO oxidation with OH. The most plausible reaction pathway of methanol oxidation on NiO (100) is predicted to be CH3OH -> CH3O -> CH2O -> CHO -> CHOOH -> COOH -> CO2. The reported facile, simple, low-cost and method provides an avenue for the rational design and synthesis of 2D NiO porous nanostructured electrode materials for DMFC and beyond. (C) 2021 Elsevier Ltd. All rights reserved.

Rational utilization of biomass waste in creating new clean energy such as lithium-ion batteries is conducive to alleviating the energy crisis and boosting environmental protection. Herein, using peanut shells as the carbon source, a MnO/C composite material was successfully prepared through an eco-environmental and facile approach based on hydrothermal treatment and pyrolysis. The resultant MnO/C composite material demonstrated a hierarchical porous structure and MnO particles with irregular morphology were embedded in the pores. When used in a lithium-ion battery, the material exhibited much better lithium storage properties than those for pristine MnO and peanut shell-derived carbon. In 0.0-3.0 V, the composite material can supply an initial specific capacity of 1169.5 mA h g(-1), with a capacity retention ratio of 84.9 % after 200 electrochemical cycles. Even at 2400 mA g(-1), the material can still offer a discharge capacity of 532.3 mA h g(-1), manifesting an outstanding rate performance. The enhanced lithium storage properties of the composite material are attributed to the support of the porous carbon matrix derived from peanut shells, which are not only conducive to improving conductivity but also capable of buffering the volume expansion/shrinkage caused by lithiation/delithiation during charge/discharge processes.

Recently,Ti3C2Tx-a family of early transition metal carbides,called MXenes,were discovered and applied to the catalyst supporter of polymer electrolyte membrane fuel cells (PEMFCs),which showed enhanced durability and improved oxygen reduction reaction(ORR) activity. Here,we synthesized a catalyst by mixing homogeneous 2D Ti3C2Tx nanosheets solution with one-dimensional(1D)carbon nanotubes(CNT)and chloroplatinic acid. The hybrid structure catalyst (Pt-CNT/TiC)is consisted of zero-dimensional 0D Pt nanoparticles,1D carbon nanotubes(CNT) and 2D Ti3C2Tx nanosheets. Compared with the catalyst without adding Ti3C2Tx(Pt-CNT),the Pt-CNT/TiC catalyst shows high electro-catalysis activity for methanol oxidation reaction(MOR)and oxygen reduction reaction(ORR).

To drive the Fe-based application for the Oxygen Reduction Reaction (ORR) in alkali media, this work found the Carbon Nanotube supported Fe-Polyaniline (Fe-PANI/CNT) catalyst from controlled Molecular Self-assembly (MS) method is comparable to the commercial Pt/C catalyst in mass current density and ORR stability, but with large gap on specific current density. This can be due to that the controlled MS method help establish the most active site of Fe-N coordination in the PANI pore, whose hydrophilic state inhibits O2 transfer and whose poor conductivity restricts O2 utilization jointly. In the meanwhile, we revealed that the enormous impact of OH adsorption (OHad) on ORR activity and stability, exhibiting negative results on the Pt/C catalyst but beneficial results for Fe-based catalysts, especially in the “indirect 2e+2e pathway” relating to the inner and outer-sphere electron transfer processes. All these progress facilitate the clarification for the structure-catalysis and encourage preparation towards controlled MS methods.

In this paper, we report a hierarchical structure Ni(OH)2 nanosheet array electrode by a directed liquid-phase approach, which consists of amorphous Ni(OH)2 interface layer and crystalline ultra-thin porous Ni(OH)2 nanosheets top layer. The testing results present that the maximum discharge capacity of 404.8mAhg−1 at lower rate of 1.4Ag−1 and the ultra-high capacity of 1714Fg−1 at super-high rate of 50Ag−1 without decay after 3000 cycles was obtained, respectively. This unique design provides excellent flexibility, long and stable cycle lifetimes, high energy and power densities simultaneously.

A powder of oxyfluorotitanate Na3TiOF5 crystals is acquired as an intermediate product during the synthesis of anatase titanium dioxide (TiO2) nanosheets with a large percentage of exposed reactive {001} facets. By application of transmission electron microscopy techniques, mainly energy dispersive spectroscopy and selected-area electron diffraction, coherent domain variants of Na3TiOF5 are shown to possess monoclinic structure with space group P2(1)/n. The occurrence of these orientation domain variants is attributed to the reduction of crystal symmetry as a result of the phase transition from the high-temperature cubic phase to the low-temperature monoclinic phase. Through a detailed group theory analysis, the orientation domains are shown to exhibit 12 variants and 11 domain boundaries, which can be categorized into three types of perpendicular twins and two types of antiparallel twins. This work may provide meaningful insight for understanding the growth mechanism of anatase TiO2 with a high percentage of reactive facets.