Electrocatalysts For Oxygen Reduction Reaction Research Articles

Single atom catalyst induced by redox reaction between iron ion and aniline monomer

The effective design of a low-cost, efficient, and stable non-noble metal electrocatalyst to substitute the noble metal electrocatalyst for oxygen reduction reaction is highly significant. Even though atomically dispersed metal catalyst shows excellent catalytic activity with maximized atom efficiency, the challenge often lies in achieving uniform distribution for single-atom catalysts owing to their tendency to aggregate. In this work, we present a sequential method that involves the reduction of iron (Fe) mediated by aniline (anchored on support), followed by pyrolysis to fabricate the Fe-Nx moieties and achieve the high density of single atom active sites. The resulting Fe SA 900 catalyst exhibited a half-wave potential of 0.84 V vs. reversible hydrogen electrode (RHE) for oxygen reduction reaction and outstanding stability in alkaline condition. Using various analysis techniques and electrochemical analysis, we demonstrated that the electrocatalytic activity of the catalyst arises from Fe single atom. To validate the practical applicability of Fe-N-C catalysts, we conducted an anion exchange membrane fuel cell (AEMFC) test, which demonstrated a high performance of 212 mW cm−2 at maximum power density. This study proves that the effectiveness of a sequential strategy adopting redox reaction and following pyrolysis for precise synthesis of a single atom Fe catalyst.

Boosting the Electrocatalytic Oxygen Reduction Activity of MnN4-Doped Graphene by Axial Halogen Ligand Modification.

Exploring highly active electrocatalysts as platinum (Pt) substitutes for the oxygen reduction reaction (ORR) remains a significant challenge. In this work, single Mn embedded nitrogen-doped graphene (MnN4) with and without halogen ligands (F, Cl, Br, and I) modifying were systematically investigated by density functional theory (DFT) calculations. The calculated results indicated that these ligands can transform the dyz and dxz orbitals of Mn atom in MnN4 near the Fermi-level into dz2 orbital, and shift the d-band center away from the Fermi-level to reduce the adsorption capacity for reaction intermediates, thus enhancing the ORR catalytic activity of MnN4. Notably, Br and I modified MnN4 respectively with the lowest overpotentials of 0.41 and 0.39 V, possess superior ORR catalytic activity. This work is helpful for comprehensively understanding the ligand modification mechanism of single-atom catalysts and develops highly active ORR electrocatalysts.

Designing highly efficient electrocatalyst for ORR and OER of transition metals doped g-C9N7: A density functional theory study

The application of fuel cells and metal-air batteries is limited by the rate of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Thus, the aim of this study is to find an efficient electrocatalyst to accelerate the reaction rate by DFT method. The structures of VIIB, VIII, IB, and IIB groups transition metals doped g-C9N7 as superb bifunctional electrocatalysts for ORR and OER are probed. The results show that Fe-, Pd-, and Au–C9N7 possess the superb ORR performance with the ORR overpotentials values of 0.35, 0.40, and 0.39 V, which gives them better performance than Pt(111). Moreover, Rh-, Pd-, and Pt–C9N7 have better OER performance with the OER overpotentials values of 0.30, 0.57, and 0.43 V, which makes them comparable to RuO2(110) and IrO2(110). Finally, the calculated bifunctional index (BI) results show that Pd–C9N7 can be used as an excellent bifunctional electrocatalyst because it has a minimum BI value of 0.97 V. This research has the potential to provide valuable theoretical direction into the use of M − C9N7 as electrocatalysts for both the ORR and OER.

Long‐Durability, Surfactant‐Free, and Bifunctional Ir‐Doped Pt3Co/MWCNTs Electrocatalysts towards ORR and OER in Acidic Media

AbstractDeveloping cost‐effective, high‐performance, and durable electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is pivotal for advancing hydrogen energy conversion and storage technologies. Simultaneously, establishing scalable methods for their production is essential for the widespread adoption of these renewable energy solutions. In this study, we present a successful large‐scale synthesis of surfactant‐free iridium‐doped Pt−cobalt nanoparticles supported on multiwalled carbon nanotubes (Ir−Pt3Co/MWCNTs). This composite demonstrates significantly enhanced ORR and OER activity compared to commercial Pt/C and IrO2 in acidic environments. The Ir−Pt3Co/MWCNTs catalyst composite exhibits a low overpotential of 357 mV at 10 mA cm−2 and a remarkable mass activity of 0.594 A/mgPt. Investigating the influence of Ir doping content on ORR and OER, we found that Pt3Co0.6Ir0.4/MWCNTs showcased the most superior activity in both reactions. We present a reproducible protocol for the synthesis of surfactant‐free Ir−Pt3Co nanoparticles supported on MWCNTs, yielding a bifunctional catalyst capable of efficiently catalyzing both ORR and OER with outstanding efficiency and stability in acidic media. Detailed X‐ray photoelectron spectroscopy (XPS) analysis elucidates the electron transfer between atoms, optimizing the electronic structure and adjusting the position of the d‐band. This optimization enhances the electrocatalytic activity and structural stability of the catalysts, contributing to their superior performance in ORR and OER.

In-situ construction of ionic liquid salt-derived graphene-like dual-heteroatoms doping engineering as efficient metal-free electrocatalyst for oxygen reduction reaction

Metal-free heteroatom-doped carbon catalysts can effectively eliminate the degradation and pollution problems caused by metal dissolution. However, single heteroatom doping often restricts the regulation of geometric and electronic structures for oxygen reduction reaction (ORR) electrocatalysts. Herein, a dual atomic doping engineering to optimize the electronic structure and local coordination environment of ionic liquid salt-derived graphene-like host material as an efficient metal-free electrocatalyst for ORR. The resultant PNG catalyst with a typical nanosheets morphology with a high specific surface area and unique hierarchical porous structure. Benefiting from the uniform doping of P, N heteroatoms, graphene-like structure, optimized electronic structure and coordination environment, thus-prepared PNG-2 exhibits outstanding ORR activity, which the onset potential and half-potential are negatively shifted by around 70 mV and 46 mV, respectively, as compared to the commercial Pt/C (20 wt.%) for ORR. Furthermore, the PNG-2 exhibits the higher diffusion limiting current density, superior long-term stability as well as excellent resistance to methanol oxidation than Pt/C. Experimental studies and density functional theory (DFT) calculations reveal that the enhanced chemisorption of oxygen species (*OOH, *O and *OH) onto the P and N sites of the PNG catalysts can effectively accelerate the charge transfer kinetics and promote a favorable ORR performance.

A Superior Bifunctional Electrocatalyst in Which Directional Electron Transfer Occurs Between a Co/Ni Alloy and Fe─N─C Support.

Stable, efficient, and economical bifunctional electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are needed for rechargeable Zn-air batteries. In this study, a directional electron transfer pathway is exploited in a spatial heterojunction of CoyNix@Fe─N─C heterogeneous catalyst for effective bifunctional electrolysis (OER/ORR). Thereinto, the Co/Ni alloy is strongly coupled to the Fe─N─C support through Co/Ni─N bonds. DFT calculations and experimental findings confirm that Co/Ni─N bonds play a bridging role in the directional electron transfer from Co/Ni alloy to the Fe─N─C support, increasing the content of pyridinic nitrogen in the ORR-active support. In addition, the discovered directional electron transfer mechanism enhances both the ORR/OER activity and the durability of the catalyst. The Co0.66Ni0.34@Fe─N─C with the optimal Ni/Co ratio exhibits satisfying bifunctional electrocatalytic performance, requiring an ORR half-wave potential of 0.90V and an OER overpotential of 317mV at 10mA cm-2 in alkaline electrolytes. The assembled rechargeable zinc-air batteries (ZABs) incorporating Co0.66Ni0.34@Fe─N─C cathode exhibits a charge-discharge voltage gap comparable to the Pt/C||IrO2 assembly and high robustness for over 60h at 20mA cm-2.

CuFe nanoparticles coupled Cu–Nx for enhancing oxygen reduction reaction

For the large-scale development of zinc-air batteries (ZABs), designing efficient, and cost-effective oxygen reduction reaction (ORR) electrocatalysts is crucial yet challenging. Herein, CuFe nanoparticles coupled with Cu–Nx active sites co-anchored on 2D nitrogen–doped porous carbon nanosheets (CuFe@Cu–N–C) were obtained by the pyrolysis of Cu–MOF–74, nitrogen source, and ferric salt. The 2D porous carbon structure and the coupling effect between CuFe nanoparticles and Cu–Nx active sites endowed the CuFe@Cu–N–C electrocatalyst with excellent ORR electrocatalytic performance. Consequently, the CuFe@Cu–N–C electrocatalyst exhibited enhanced ORR activity with a higher half–wave potential than Cu–N–C, surpassing even that of the commercial 20 % Pt/C by 21 mV in alkaline media. Additionally, the CuFe@Cu–N–C electrocatalyst exhibited superior ORR stability to commercial 20 % Pt/C. Primary ZABs assembled with the CuFe@Cu–N–C as the cathode ORR electrocatalyst also showed excellent electrochemical properties. The work shows that the prepared CuFe@Cu–N–C electrocatalyst can serve as an ideal alternative to Pt-based catalysts for ZABs.

Graphene benefits penta-nitrogen coordinated iron and catalytic stability of oxygen reduction reaction

Metal-nitrogen-carbon catalytic material, generally thought as a promising low-cost electrocatalyst of oxygen reduction reaction (ORR), surfers from long-term catalytic durability for fuel cell and metal-air battery. Here, we describe an approach of synthesizing electrochemically exfoliated graphene supported penta-nitrogen coordinated iron exhibiting encouraging ORR catalytic activity and durability. The synthesized catalyst exhibits high half-wave potentials in alkaline medium (E1/2 0.940 V) enabling high-performance zinc-air battery and in acidic condition for durable fuel cell with a high peak power density (630 mW cm−2). The current density of a proton exchange membrane fuel cell loading the catalyst as cathode tends to decay little after initial hours under H2-air measurement, remarkably inhibiting commonly decline tendency of iron–nitrogen-carbon catalysts. DFT calculation combined with extensive experimental investigations demonstrate that penta-nitrogen coordinated iron supported by graphene is thermodynamically stable, and thus benefits the catalytic stability of ORR.

Three-dimensional porous structured cobalt- and nitrogen-doped carbon nanotube electrocatalyst derived from cobalt-based zeolitic imidazolate framework nanoleaves for high performance zinc-air battery

The development of efficient and cost-effective electrocatalysts to overcome the intrinsic sluggish kinetics of the oxygen reduction reaction (ORR) in zinc-air batteries is crucial. In this study, we introduce a strategy that integrates a template-assisted synthesis with subsequent thermal treatment to fabricate an active and stable cobalt-based nitrogen-doped carbon electrocatalyst, denoted as Co-N-CNT. The strategy adjusts the disordered architecture of the zeolitic imidazolate framework (ZIF) through the synergistic effect of bimetallic species, restricted the growth of zeolitic imidazolate framework nanoleaves (ZIF-L) using salt templates, and directed the transformation from a two-dimensional blade-like morphology to a three-dimensional multi-tiered composite structure. Notably, the Co-N-CNT-800 sample, synthesized at an optimized pyrolysis temperature of 800 °C, exhibits a half-wave potential of 0.89 V and demonstrates stability with sustained cycling over 21 h, which is comparable to the performance of commercial Pt/C electrocatalysts. Moreover, when employed as the cathode in zinc-air batteries, Co-N-CNT-800 not only surpasses Pt/C in terms of power density but also exhibits long-term charge/discharge stability. This findings offer a viable pathway for the design of active and cost-effective ORR electrocatalysts, holding promise for applications in the electrochemical energy storage and conversion systems.

Graphene-supported MN4 single-atom catalysts for multifunctional electrocatalysis enabled by axial Fe tetramer coordination

Multifunctional electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) are crucial for development of the key electrochemical energy storage and conversion devices, for which single-atom catalyst (SAC) has present great promises. Very recently, some experimental works showed that structurally well-defined ultra-small transition-metal clusters (such as Fe and Co tetramers, denoted as Fe4 and Co4, respectively), can efficiently modulate the catalytic behavior of SACs by axial coordination. Herein, taking the graphene-supported MN4 SACs as representatives, we theoretically explored the feasibility of realizing multifunctional SACs for ORR, OER and HER by this novel axial coordination engineering. Through extensive first-principles calculations, from 23 candidates, IrN4 decorated with Fe4 (IrN4/Fe4) is identified as the promising trifunctional catalyst with the theoretical overpotential of 0.43, 0.51 and 0.30 V for OER, ORR and HER, respectively. RhN4/Fe4 and CoN4/Fe4 are recognized as potential OER and ORR bifunctional catalysts. In addition, NiN4/Fe4 exhibits the best ORR activity with an overpotential of 0.30 V, far superior to the pristine NiN4 SAC (0.88 V). Electronic structure analyses reveal that the significantly enhanced ORR/OER activity can be ascribed to the orbital and charge redistribution of Ni/Ir active center, resulting from its electronic interaction with Fe4 cluster. This work could stimulate and guide the rational design of graphene-based multifunctional SACs realized by axial coordination of small TM clusters, and provide insights into the modulation mechanism.

Ultralow palladium doped C4N as a potential bifunctional electrocatalyst for zinc-air battery

It is an important task for designing a facile bifunctional electrocatalyst that is applied to a zinc-air battery (ZAB). Herein, the 2D C4N is synthesized by hydrothermal method, and ultralow noble metal palladium (Pd) is doped into the C4N to form Pd-C4N. The Pd-C4N has a low ΔE of 0.76 V in 0.1 M KOH, which is a good candidate as the bifunctional electrocatalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the ZABs. This work provides a design idea of modified carbon-based material for bifunctional electrocatalysts.

Reactivity and Durability of Covalent Organic Frameworks Derived Co‐Based Hybrid Bifunctional Electrocatalysts for Zinc‐Air Batteries

AbstractDeveloping bifunctional non‐precious metal electrocatalysts of superior reactivity and durability is essential. Herein, we report a class of phthalocyanine‐based covalent organic frameworks as self‐sacrificial precursors derived Co‐based hybrid electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The fabricated Co‐COFs/CNT‐700 catalysts displayed highly efficient ORR properties with a half‐potential of 0.83 V, while its half‐wave potential in alkaline solution at a current density of 10 mA cm−2 is 1.70 V in the OER test, reflecting exceptional OER activity. Moreover, zinc‐air batteries assembled with Co‐COFs/CNT‐700 catalysts exhibit a marginally higher power density (114 mW cm2) than traditional Pt/C−IrO2 batteries in an air atmosphere, along with an enhanced cycling stability (5.1 % potential loss after 65 h). This work may pave a facile and efficient approach for fabricating electrocatalytic materials with controllably introduced metals and heteroatoms.

FeMnO3/CNT as a synergistic bifunctional electrocatalyst for oxygen reduction and oxygen evolution reactions in alkaline medium

The development of highly effective and low-cost electrocatalysts for energy conversion and storage devices is triggered by the sluggish kinetics of oxygen reduction and evolution reactions. Perovskite-based oxides are identified as potential ORR and OER electrocatalysts in an alkaline medium. Thus, the present study discusses the synthesis and characterization of FeMnO3/CNT as a bifunctional catalyst with a low potential gap of 0.89 V. The FeMnO3/CNT composite was synthesized by the solution combustion method and characterized using spectroscopic and electron microscopic techniques. The increase in the ID/IG ratio obtained from the Raman spectra of the FeMnO3/CNT composite with respect to bare CNT indicates the functionalization of CNT. The ORR and OER characteristics of the FeMnO3/CNT composite were analyzed with rotating ring disc electrode and rotating disc electrode measurements. The LSV curve of the FeMnO3/CNT composite synthesized with 0.3g of CNT show better ORR and OER activity. The ORR activity measurements of the composite done in 0.1 M KOH electrolyte show a good onset potential of 0.95 V vs. RHE and a half-wave potential of 0.74 V. The HPRR studies show that the ORR reaction mechanism follows a 2e− + 2e− reduction pathway. The OER measurements in an alkaline medium show an onset potential of 1.63 V vs. RHE with a Tafel slope of 115.3 mV dec−1. Also, this work gives an insight into the fundamental understanding of the synergy between the perovskite and CNT, leading to an enhanced ORR and OER catalytic activity. In addition, the material exhibits good stability for ORR and OER stability studies.

Modulating the Bader Charge Transfer in Single p-Block Atoms Doped Pd Metallene for Enhanced Oxygen Reduction Electrocatalysis.

Metallene is considered as an emerging family of electrocatalysts due to its atomically layered structure and unique surface stress. Here we propose a strategy to modulate the Bader charge transfer (BCT) between Pd surface and oxygenated intermediates via p-d electronic interaction by introducing single-atom p-block metal (M=In, Sn, Pb, Bi) into Pd metallene nanosheets towards efficient oxygen reduction reaction (ORR). X-ray absorption and photoelectron spectroscopy suggests that doping p-block metals could facilitate electron transfer to Pd sites and thus downshift the d-band center of Pd and weaken the adsorption energy of O intermediates. Among them, the developed Bi-Pd metallene shows extraordinarily high ORR mass activity of 11.34 A mgPd -1 and 0.86 A mgPd -1 at 0.9 V and 0.95 V in alkaline solution, respectively, representing the best Pd-based ORR electrocatalysts ever reported. In the cathode of a Zinc-air battery, Bi-Pd metallene could achieve an open-circuit voltage of 1.546 V and keep stable for 760 h at 10 mA cm-2. Theoretical calculations suggest that the BCT between Pd surface and *OO intermediates greatly affects the bond length between them (dPd-*OO) and Bi doping could appropriately reduce the amount of BCT and stretch the dPd-*OO, thus enhancing the ORR activity.

ZIF-8-derived nanocarbon composite-based highly active platinum group metal-free bimetallic electrocatalysts for oxygen reduction reaction in proton exchange membrane fuel cells

Non-precious metal catalysts are ideal low-cost substitutes of Pt/C for the sluggish oxygen reduction reaction (ORR), despite the serious stability challenges in proton exchange membrane fuel cells (PEMFC) to alleviate the energy crisis and environmental problems. Platinum group metal (PGM)-free bimetallic composite electrocatalysts are assumed to be an interesting route to be investigated to address the stability and ORR selectivity related issues in PEMFC conditions. In this regard, we propose a simple and facile synthesis route by a composite of multi-walled carbon nanotubes and zeolitic imidazolate framework (ZIF)-8 followed by impregnating dual transition metals (FeMn, FeCo, and CoMn) and evaluate their ORR activity in acid media and PEMFC performance. Various catalyst materials are prepared and optimized to achieve the highest electrocatalytic performance. The prepared catalysts are characterized by various physico-chemical methods to elucidate their textural, structural, and morphological properties. The high ORR electrocatalytic activity and selectivity of the catalyst are reported in terms of half-wave potential and low H2O2 yield as determined by the rotating ring-disk electrode method. The significant electrochemical stability under accelerated durability test and high peak power density (787 mW cm−2) in H2-O2 PEMFC made these catalysts as potential candidates for efficient alternatives to PGMs in the fuel cell cathodes.

Atomically dispersed dual iron and manganese anchored nitrogen doped reduced graphene as robust cathode catalyst for direct methanol fuel cell and aluminium air battery

A noble metal-free atomically dispersed dual metal (Fe and Mn) anchored nitrogen (N)-doped reduced graphene oxide (rGO) is synthesized as a high-performance oxygen reduction reaction (ORR) electrocatalyst for alkaline direct methanol fuel cell and aluminium-air battery (AAB). The as-synthesized FeMn-NrGO catalyst exhibits a half-wave potential of 0.84 V for ORR and a low onset potential of 0.96 Vvs (RHE). The theoretical study reveals that the synergetic coupling of Mn and Fe with pyridinic and pyrrolic nitrogen weakening adsorption bond strength of the O* intermediates to the active site of the catalyst, thereby improving the for ORR performance. The synthesized Fe3Mn1-NrGO cathode catalyst assembled alkaline direct methanol fuel cell (DMFC) demonstrates a peak power density of 65 mW/cm2 extending an effective strategy to enhance the ORR kinetics of the non-noble metal-based catalyst for fuel cell application. Furthermore, the synthesized Fe3Mn1-NrGO also exhibits excellent ORR activity in 3.5 wt% NaCl solution and demonstrates a peak power density of 11.2 mW/cm2 aqueous NaCl electrolyte-based AAB system.

Compressively Strained Fe3O4 in Core-Shell Oxygen Reduction Electrocatalyst Boosts Zinc-Air Battery Performance.

Fe3O4 is barely taken into account as an electrocatalyst for oxygen reduction reaction (ORR), an important reaction for metal-air batteries and fuel cells, due to its sluggish catalytic kinetics and poor electron conductivity. Herein, how strain engineering can be employed to regulate the local electronic structure of Fe3O4 for high ORR activity is reported. Compressively strained Fe3O4 shells with 2.0% shortened Fe─O bond are gained on the Fe/Fe4N cores as a result of lattice mismatch at the interface. A downshift of the d-band center occurs for compressed Fe3O4, leading to weakened chemisorption energy of oxygenated intermediates, and lower reaction overpotential. The compressed Fe3O4 exhibits greatly enhanced electrocatalytic ORR activity with a kinetic current density of 27 times higher than that of pristine one at 0.80V (vs reversible hydrogen electrode), as well as potential application in zinc-air batteries. The findings provide a new strategy for tuning electronic structures and improving the catalytic activity of other metal catalysts.

Synergistic Advancements in Battery-Grade Energy Storage: AgCoS@MXene@AC Hybrid Electrode Material as an Enhanced Electrocatalyst for Oxygen Reduction Reaction

The extreme usage of fossil fuels and the rising conservation deterioration have made developing clean, renewable energy essential. Among the most promising methods for addressing the world’s energy dilemma are electrochemical energy storage devices (EES); batteries and supercapacitors (SCs) are two typical components in this class. Supercapacitors are incredibly impressive since they can store energy remarkably in seconds. In this work, we present a highly effective electrode material (AgCoS@MXene) for supercapattery device application that is produced hydrothermally. We examined the morphology and crystallinity of the synthesized materials using SEM and XRD studies. The synthesized compounds were subjected to a thorough electrochemical performance study employing a three-electrode configuration in a 1 M KOH electrolyte. AgCoS@MXene demonstrated an exceptional Qs of 943.22 C g−1 at a current density of 2.0 A g−1. We formed a supercapattery device (AgCoS@MXene//AC) with AgCoS@MXene as the positive electrode and activated carbon (AC) as the negative electrode. The supercapattery device was demonstrated to have a high specific capacity of 315.22 C g−1, a power density of 1275 W kg−1, and an energy density of 35.94 Wh kg−1. In addition, 5000 charging and discharging cycles were used to assess the device’s long-term longevity. The findings indicated that the device preserved nearly 82% of its initial capacity. Besides, the hybrid electrode is used for the electrocatalytic activity for the oxygen reduction reaction. These promising findings imply that AgCoS@MXene is a beneficial electrode material for upcoming energy storage devices to enhance the electrocatalytic activity for the oxygen reduction reaction.

Facile Carbothermal Synthesis of Metal Phosphides-Based Multifunctional Electrocatalysts via Polyaniline Doped with Phosphoric Acid

Transition metal phosphides (TMPs) and their composites are promising non-platinum electrocatalysts for hydrogen evolution (HER), oxygen evolution (OER), and oxygen reduction (ORR) reactions. But traditional methods to obtain these electrocatalysts are usually multi-step and include the participation of hazardous phosphorus compounds during phosphidation. Here, the possibility of using a polyaniline doped with phosphoric acid (PANI∙H3PO4)—as a source of C, N and P simultaneously - to obtain composites based on N,P-doped carbon and nano- and/or submicron TMP particles as HER, OER and ORR electrocatalysts is demonstrated. The pyrolysis of PANI∙H3PO4 together with Co, Ni, Mo, or Fe salt allows the formation of such composite electrocatalysts by the carbon thermal reduction route. Regardless of the pH of the electrolyte, the MoP-based electrocatalyst is characterized in HER by the smallest Tafel slope and overpotential of hydrogen evolution and also exhibits high stability during long-term operation. At the same time, other composites are multifunctional electrocatalysts possessing activity not only in HER, but also in OER and ORR. The proposed approach can be a starting point for a simple, universal in choice of d-metal, and environmentally attractive preparation of multifunctional TMP-based electrocatalysts with further improvement of their performance.

Nghiên cứu tính chất điện hóa, cấu trúc và khả năng xúc tác khử điện hóa oxygen của vật liệu Fe-Porphyrin trên bề mặt HOPG

This paper describes an efficient approach to fabricate Fe-Porphyrin thin film deposited on highly oriented pyrolytic graphite substrate (HOPG/FePP) via the dip-coating method serving as a novel electrocatalyst for oxygen reduction reaction (ORR) in acidic medium. The electrochemical, morphological behaviors and surface structure at the molecular level of the HOPG/FePP as well as its catalytic activities were characterized upon employing a state-of-the-art toolbox including cyclic voltammetry (CV), atomic force microscopy (AFM), electrochemical scanning tunneling microscopy (EC-STM) and linear sweep voltammetry (LSV). Consequently, the HOPG/ FePP thin film exhibited a significantly enhanced catalytic activity for ORR under applied experimental conditions.