Oxygen Reduction Reaction Durability Research Articles

2D Co-N-C catalysts derived by 1D CoxZn1-xO hexagonal microrods for oxygen reduction reaction

A novel and feasible strategy to construct 2D Co-N-C catalyst from one-dimensional (1D) CoxZn1-xO microrod is reported. In the strategy, 1D CoxZn1-xO microrods are firstly transformed into CoxZn1-xO@CoZn-ZIF hexagonal core-shell microrods by regulating the reaction conditions of high-pressure vapor-solid transformation, and subsequently pyrolyzed at high temperature to form Co-N-C hexagonal microtubes, which are finally fractured along its edges under the action of thermal stress, evolving gradually to Co-N-C nanosheets. Besides, by investigating the effects of Co doping contents, a catalyst with optimal chemical and structural properties and more highly accessible Co-N4 active sites has achieved respectable activity and stability for the oxygen reduction reaction (ORR) in alkaline media. Among them, Co0.3-N-C NS exhibits superior ORR performance (Eon=1.01 V, E1/2 = 0.87 V), durability and tolerance to methanol than those of commercial Pt/C catalysts (Eon=0.99 V, E1/2 = 0.85 V) in alkaline media.

Carbon‐Embedded Pt Alloy Cluster Catalysts for Proton Exchange Membrane Fuel Cells

AbstractMinimizing the use of platinum (Pt) in proton exchange membrane fuel cells (PEMFCs) is crucial for expanding the PEMFC market. The most straightforward approach would be to reduce the size of Pt particles. However, small Pt clusters, particularly those <2 nm in size, typically exhibit reduced activity for the oxygen reduction reaction (ORR) due to the overly strong adsorption of oxygen intermediates. Additionally, these small Pt clusters tend to degrade more quickly, resulting in lower durability. In this study, carbon‐embedded Pt alloy cluster catalysts (PtFe, PtCo, PtNi) that demonstrate high activity and durability in the PEMFC cathode are presented. Density functional theory calculations indicate that carbon atoms stably adsorb onto the Fe sites of PtFe clusters, making the neighboring Pt sites active for ORR with an optimal adsorption strength for oxygen intermediates. This research can pave the way for developing durable and efficient ORR catalysts while significantly reducing Pt usage in PEMFCs.

Strong Interaction between Titanium Carbonitride Embedded in Mesoporous Carbon Nanofibers and Pt Enables Durable Oxygen Reduction.

Platinum (Pt) supported on high surface area carbon has been the most widely used electrocatalyst in proton exchange membrane fuel cell (PEMFC). However, conventional carbon supports are susceptible to corrosion at high potentials, leading to severe degradation of electrochemical performance. In this work, titanium carbonitride embedded in mesoporous carbon nanofibers (m-TiCN NFs) are reported as a promising alternative to address this issue. Benefiting from the interpenetrating conductive pathways inside the one-dimensional (1D) nanostructures and the embedded TiCN nanoparticles (NPs), m-TiCN NFs exhibit excellent stability at high potentials and interact strongly with Pt NPs. Subsequently, m-TiCN NFs-supported Pt NPs deliver remarkably enhanced oxygen reduction reaction (ORR) activity and durability, with negligible activity decay and less than 5% loss of electrochemical surface area（ECSA） after 50000 cycles. Moreover, the fuel cell assembled by this catalyst delivers a maximum power density of 1.22W cm-2 and merely 3% loss after 30000 cycles of accelerated durability tests under U.S. Department of Energy (DOE) protocols. The improved ORR activity and durability are attributed to the superior corrosion resistance of the m-TiCN NF support and the strong interaction between Pt and m-TiCN NFs.

Boosting oxygen reduction durability by embedding Co9S8 nanoparticles into Co single atoms anchored porous carbon frameworks

Developing an efficient and low-cost oxygen reduction electrocatalyst is essential for the application of aqueous zinc-air batteries (ZABs). Herein, we report a facile adsorption-confined pyrolysis strategy to fabricate the hybrid electrocatalyst (denoted as Co9S8/CoSA-PC) by embedding Co9S8 nanoparticles into Co single atoms (Co-SAs) anchored porous carbon sheets for boosting oxygen reduction reaction (ORR) durability. In this strategy, the Co2+ ions are first absorbed into oxygen-rich porous carbon nanosheets and further form the Co-SAs with the help of thiourea in the following pyrolysis procedure, which is believed to be able to confine the generated Co9S8 nanoparticles into carbon frameworks due to their interface interaction. Benefiting from the synergistic effect of different components, the obtained Co9S8/CoSA-PC electrocatalyst for ORR exhibits outstanding catalytic activity with a half-wave potential of 0.82 V and a distinguished long-term durability with a current retention of 80 % after cycling 80 h under alkaline conditions, which is superior to commercial Pt/C. Moreover, the assembled ZABs with Co9S8/CoSA-PC as cathodic catalyst deliver a high specific capacity of 764 mAh gZn−1 at 10 mA cm−2 and the outstanding peak power density of up to 221.4 mW cm−2. This work provides a novel structure design strategy to prepare transition metal sulfide-based electrocatalysts with superior durability for ORR.

Ag@Co/Zn N‐Doped Carbon as Antibacterial Oxygen Reduction Catalysts for Microbial Fuel Cells

Biofouling of air cathode surface decreases the electricity generation performance of membrane‐free microbial fuel cells (MFCs). Ag@Co/Zn N‐doped carbon (Ag@Co/Zn‐NC) is designed as an antibacterial oxygen reduction reaction (ORR) catalyst to inhibit biofouling on the cathode surface. The Co/Zn‐NC active component promotes ORR catalytic activity through the advantages of well‐distributed Co nanoparticles and numerous active sites. Superficial Ag nanoparticles act as antibacterial active species to inhibit bacterial proliferation and suppress biofilm growth. Ag@Co/Zn‐NC catalyst prevents bacterial adhesion and biofilm formation, effectively preventing excessive biofouling on the cathode surface. The antibacterial catalyst maintains a high catalytic activity and good ion diffusion properties without the adverse effects of biofouling, resulting in enhanced ORR durability of the air cathode. The assembled MFCs achieve high electricity generation during long‐term cyclic operation. The maximum power density retention percentage (82.6%) is higher than that of Co/Zn‐NC MFC (65.3%) and Pt/C MFC (52.4%) after continuous operation for 1200 h. Excellent operational durability is revealed for the air‐cathode MFCs assembled with the antibacterial ORR catalyst during the cyclic process. The novelty of this study is that the design of antibacterial catalysts inhibits the excessive growth of the cathode biofilm to improve the cyclic electricity generation performance of MFCs.

Atomic controlled shell thickness on Pt@Pt3Ti core-shell nanoparticles for efficient and durable oxygen reduction

The exploitation of durable and highly active Pt-based electrocatalysts for the oxygen reduction reaction (ORR) is essential for the commercialization of proton exchange membrane fuel cells (PEMFCs). Herein, we designed Pt@Pt3Ti core-shell nanoparticles with atomic-controllable shells through precise thermal diffusing Ti into Pt nanoparticles for effective and durable ORR. Combining theoretical and experiment analysis, we found that the lattice strain of Pt3Ti shells can be tailored by precisely controlling the thickness of Pt3Ti shell in atomic-scale on account of the lattice constant difference between Pt and Pt3Ti to optimize adsorption properties of Pt3Ti for ORR intermediates, thus enhancing its performance. The Pt@Pt3Ti catalyst with one-atomic Pt3Ti shell (Pt@1L-Pt3Ti/TiO2-C) demonstrates excellent performance with mass activity of 592 mA mgPt−1and durability nearly 19.5-fold that of commercial Pt/C with negligible decay (2%) after 30,000 potential cycles (0.6-1.0 V vs. RHE). Notably, at higher potential cycles (1.0 V-1.5 V vs. RHE), Pt@1L-Pt3Ti/TiO2-C also showed far superior durability than Pt/C (9.6% decayed while 54.8% for commercial Pt/C). This excellent stability is derived from the intrinsic stability of Pt3Ti alloy and the confinement effect of TiO2-C. The catalyst's enhancement was further confirmed in PEMFC configuration.

Effective Promotion of the Activity and Stability of Cathodes for Protonic Ceramic Fuel Cells

AbstractProtonic ceramic fuel cells (PCFCs) are emerging as effective devices for their excellent capability of converting energy. However, the sluggish oxygen reduction reaction (ORR) and poor durability of cathodes greatly limit their widespread commercialization. Herein, a multi‐cationic oxide nano‐catalyst with a nominal composition of Pr0.2Ce0.2Ni0.2Co0.2Fe0.2Ox (denoted as PCNCFO) is designed and reported, which significantly enhanced the ORR activity and durability of a typical PrBaCo2O5+δ (PBC) cathode. The PCNCFO‐coated PBC cathode delivered impressive cell performance with a small polarization resistance of only 0.18 Ω cm2 at 600 °C on symmetrical cells and a high peak power density (PPD) of 1.31 W cm−2 at 650 °C on single cells. Meanwhile, the PCNCFO‐coated PBC cathode exhibits excellent operational stability both on symmetrical and single cells. It is indicated that the Ce oxide in the nano‐catalyst coating can react with the segregated Ba to form active species, while others can activate the surface of the cathode, as indicated by the transmission electron microscope (TEM) and distribution of relaxation time (DRT) analyses.

Multiscale Regulation of Ordered PtCu Intermetallic Electrocatalyst for Highly Durable Oxygen Reduction Reaction.

Transforming the Pt-M alloy into an ordered intermetallic is an effective strategy to improve the electrocatalytic activity and stability toward the oxygen reduction reaction (ORR). However, the synthesis of nanosized intermetallics remains challenging. Herein, we report an efficient ORR electrocatalyst, consisting of a monodisperse nanosized PtCu intermetallic on hollow mesoporous carbon spheres (HMCS). As predicted by theoretical calculations, PtCu intermetallics exhibit beneficial electronic structure, with a low theoretical overpotential of 0.33 V and enhanced Cu stability. Resulting from the multiscale modulation of catalyst structure, the O-PtCu/HMCS catalyst delivers a high mass activity of 2.73 A cm-2Pt at 0.9 V and remarkable stability. Identical location transmission electron microscopy (IL-TEM) investigations demonstrate that the rate of carbon corrosion is alleviated on HMCS, which contributes to the long-term durability. This work provides a promising design strategy for an ORR electrocatalyst, and the IL-TEM investigations offer new perspectives for the performance enhancement mechanism.

Regulating the Electronic Synergy of Asymmetric Atomic Fe Sites with Adjacent Defects for Boosting Activity and Durability toward Oxygen Reduction

AbstractThe oxygen reduction reaction (ORR) plays a fundamental role in sustainable energy technologies. However, the creation of non‐precious metal electrocatalysts with high ORR activity and durability under all pH conditions is of great significance but remains challenging. Herein, the aim is to overcome this challenge by creating a Fe single atom catalyst on a 2D defect‐containing nitrogen‐doped carbon support (Fe1/DNC) via a microenvironment engineering strategy. Microkinetic modeling reveals that FeN4(OH) moieties are the real active sites under reaction conditions. Due to the synergistic promotion effect of denser accessible FeN4(OH) moieties and defect‐induced electronic properties, Fe1/DNC catalyst achieves extraordinary ORR activity under alkaline, acidic, and neutral conditions, with half‐wave potentials of 0.95, 0.82, and 0.70 V, respectively. Moreover, a negligible performance decay is observed with this Fe catalyst in stability and methanol tolerance tests. Zn‐air battery employing Fe1/DNC delivers remarkable peak power density and long‐term operational durability. Theoretical analysis provides compelling evidence that the defects adjacent to FeN4(OH) moieties can endow an inductive effect to reshape electronic properties to balance the OOH* formation and OH* reduction. This work offers insight into the regulation of asymmetric coordination structure and electronic properties of metal sites for boosting electrocatalytic activity and stability.

Pd@CoFe Alloys on N-Doped Carbon Derived from Charred Tissue Paper as Synergistic Bifunctional Oxygen Electrocatalysts

Integrating more active components into a catalyst material could facilitate the development of multifunctional electrocatalysts for energy conversion and storage applications. In this study, we developed a multifunctional electrocatalyst, namely, Pd alloyed with Co-Fe deposited on N-doped mesoporous carbon derived from tissue paper (Pd@Co-Fe/N-TDC). The synergism in Pd@Co-Fe/N-TDC, stemming from the interatomic alloy between Pd and Co-Fe, N-doped mesoporous carbon with defective surfaces, distribution of polyhedral Pd nanoparticles, and strong metal-support interfacial interaction, resulted in significantly high electrocatalytic performance for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Pd@Co-Fe/N-TDC was found to be an efficient bifunctional oxygen electrocatalyst, and this was evidenced by a high onset potential (1.01 V) and kinetic current density (2.6 mA/cm2) for the ORR and by a low overpotential (296 mV) and a low Tafel slope value (38 mV/dec) for the OER, along with a small ΔE of 736 mV. The catalyst also exhibited high durability for both ORR and OER, even after 10000 and 5000 cycles, respectively. Theoretical assessment provides an insight into the synergism of active metal sites in Pd@Co-Fe/N-TDC, which showed its potential for use as a non-Pt electrocatalyst for energy applications.

Pt-Fe alloy supported on Fe/NC catalyst with high activity and durability for oxygen reduction reaction

In this paper, Pt-Fe alloy with low-content of Pt (2 %) was distributed uniformly over the porous Fe/NC substrate treated by nitric acid etching, with small amount of metallic Fe and Pt nanoparticles. The optimized Pt-Fe alloy on Fe/NC substrate showed higher ORR performance with the E1/2 of around 0.83 V vs. RHE as well as faster catalytic kinetics. In addition, the catalytic activity has not been decayed through an accelerated durability test after 5000 cycles CVs, indicating better catalytic stability for the alloying catalyst. The introduction of Pt elements into Fe/NC substrate increased the numbers and species of ORR active sites, invoking higher ORR activity comparing with isolated Fe/NC catalyst. The acid etching provided more defects for the substrate to anchor the active sites stably. Moreover, the synergistic effect originated from the alloying of Pt and Fe modulated the electronic structure of Pt, increasing the ORR activity with low yield of H2O2. This decreasing H2O2 yield can weaken the Fenton reaction to prevent the dissolution of Fe in the acid solution, which can improve the stability of the catalysts to meet the commercial needs for PEMFC.

High entropy La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 with tailored eg occupancy and transition metal-oxygen bond properties for oxygen reduction reaction

Forming high entropy oxide provides a feasible approach to finding a balance among moderate eg occupancy, high transition metal-oxygen (TM-O) covalency, and lattice energy, which is essential to ensure efficient and durable oxygen reduction reaction (ORR) process for perovskite lanthanide-transition metal oxides (LaTMO3). However, due to the compositional complexity, clarifying the relevance among the high entropy components, eg occupancy, TM-O properties, and ORR performance still remains a challenge. Herein, adopting the B site entropy-driven strategy, a series of LaTMO3 (TM = Cr, Mn, Fe, Co, Ni) with tunable eg occupancy and TM-O bond properties are synthesized, and the correlations between high entropy elements, eg occupancy, TM-O properties, and ORR performances are revealed quantitively based on the crystal field theory and the Phillips–Van Vechten–Levine (P–V–L) valence bond theory. High entropy La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 delivers a low overpotential of 493 mV (vs. 503 mV for LaMnO3) and a minuscule decline by only 1.7% (vs. 4.4% for LaMnO3) in half wave potential after 10,000 cycles, which can be associated with the tailored eg occupancy (1.06) and the significant enhancement in both TM-O covalency (4%) and lattice energy (691.75 kJ mol–1). This work not only demonstrates the prospects of high entropy LaTMO3 in the ORR field but also provides a new perspective for the quantitative analysis of the structure-activity relationship for high entropy oxide ORR catalysts.

Morphology engineering of self-assembled bimetallic PtCo alloy nanofoams as efficient multifunctional electrocatalysts for oxygen reduction and alcohol oxidation

The exploration of high properties of electrocatalysts is imperative for the commercialization application of fuel cells. Enhancing the catalytic activity and stability of Pt-based catalysts can be achieved by rationally designing their morphology and composition. Here, we synthesized self-assembled PtCo alloy nanofoams (ANs) catalysts with controllable surface composition and porous network. The experimental results show that prepared PtxCo1-ANs catalysts display excellent electrochemical performance in oxygen reduction reaction (ORR), methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). Interestingly, the mass activities of Pt2Co1-ANs with optimized surface composition for ORR, MOR, and EOR are 6.41, 6.64, and 7.71-fold higher than commercial Pt/C catalysts, respectively. Meantime, it also maintains high electrocatalytic durability in ORR, MOR, and EOR. Such results ascribe to the modified surface composition, optimized electronic structure, and porous interconnected nanofoam structure. These findings provide valuable insights into the design of highly active and durable multifunctional electrocatalysts with controllable shapes and composition.

Multiple Metal-Nitrogen Bonds Synergistically Boosting the Activity and Durability of High-Entropy Alloy Electrocatalysts.

The development of Pt-based catalysts for use in fuel cells that meet performance targets of high activity, maximized stability, and low cost remains a huge challenge. Herein, we report a nitrogen (N)-doped high-entropy alloy (HEA) electrocatalyst that consists of a Pt-rich shell and a N-doped PtCoFeNiCu core on a carbon support (denoted as N-Pt/HEA/C). The N-Pt/HEA/C catalyst showed a high mass activity of 1.34 A mgPt-1 at 0.9 V for the oxygen reduction reaction (ORR) in rotating disk electrode (RDE) testing, which substantially outperformed commercial Pt/C and most of the other binary/ternary Pt-based catalysts. The N-Pt/HEA/C catalyst also demonstrated excellent stability in both RDE and membrane electrode assembly (MEA) testing. Using operando X-ray absorption spectroscopy (XAS) measurements and theoretical calculations, we revealed that the enhanced ORR activity of N-Pt/HEA/C originated from the optimized adsorption energy of intermediates, resulting in the tailored electronic structure formed upon N-doping. Furthermore, we showed that the multiple metal-nitrogen bonds formed synergistically improved the corrosion resistance of the 3d transition metals and enhanced the ORR durability.

Ultradurable Pt-Based Catalysts for Oxygen Reduction Electrocatalysis

An oxygen reduction reaction (ORR) is the key half reaction of proton exchange membrane fuel cells (PEMFCs), and is highly dependent on Pt-based nanocrystals as core electrocatalysts. Despite the exceptional ORR activity from adjusting the electronic structures of surface or near-surface atoms, several serious issues, including the corrosion of carbon supports, the preferential leaching of active metal elements, the instability of surface low-coordinated atoms and the sintering/agglomeration of nanocrystals, still exist, challenging the ORR durability of developed Pt-based ORR catalysts. From the point of view of the catalyst structure design, in this review, we summarized the state-of-the-art structural regulation strategies for improving the ORR durability of Pt-based catalysts. The current limitation of Pt-based binary catalysts for ORR electrocatalysis is firstly discussed, and the detailed strategies are further classified into the optimization of supports, metal-doped alloys, core/shell structures, intermetallics and high-entropy alloys, etc. The structure–performance relationship is detailedly explained, especially emphasizing the elimination of the above restrictions. Finally, the existing challenges and future research direction are further presented, aiming at practicing the PEMFC devices of the ultradurable Pt-based catalysts.

Low‐Electronegativity Mn‐Contraction of PtMn Nanodendrites Boosts Oxygen Reduction Durability

AbstractPlatinum metal (PtM, M=Ni, Fe, Co) alloys catalysts show high oxygen reduction reaction (ORR) activity due to their well‐known strain and ligand effects. However, these PtM alloys usually suffer from a deficient ORR durability in acidic environment as the alloyed metal is prone to be dissolved due to its high electronegativity. Herein, we report a new class of PtMn alloy nanodendrite catalyst with low‐electronegativity Mn‐contraction for boosting the oxygen reduction durability of fuel cells. The moderate strain in PtMn, induced by Mn contraction, yields optimal oxygen reduction activity at 0.53 A mg−1 at 0.9 V versus reversible hydrogen electrode (RHE). Most importantly, we show that relative to well‐known high‐electronegativity Ni‐based Pt alloy counterpart, the PtMn nanodendrite catalyst experiences less transition metals’ dissolution in acidic solution and achieves an outstanding mass activity retention of 96 % after 10,000 degradation cycles. Density functional theory calculation reveals that PtMn alloys are thermodynamically more stable than PtNi alloys in terms of formation enthalpy and cohesive energy. The PtMn nanodendrite‐based membrane electrode assembly delivers an outstanding peak power density of 1.36 W cm−2 at a low Pt loading and high‐performance retention over 50 h operations at 0.6 V in H2‐O2 hydrogen fuel cells.

Low-Electronegativity Mn-Contraction of PtMn Nanodendrites Boosts Oxygen Reduction Durability.

Platinum metal (PtM, M=Ni, Fe, Co) alloys catalysts show high oxygen reduction reaction (ORR) activity due to their well-known strain and ligand effects. However, these PtM alloys usually suffer from a deficient ORR durability in acidic environment as the alloyed metal is prone to be dissolved due to its high electronegativity. Herein, we report a new class of PtMn alloy nanodendrite catalyst with low-electronegativity Mn-contraction for boosting the oxygen reduction durability of fuel cells. The moderate strain in PtMn, induced by Mn contraction, yields optimal oxygen reduction activity at 0.53 A mg-1 at 0.9 V versus reversible hydrogen electrode (RHE). Most importantly, we show that relative to well-known high-electronegativity Ni-based Pt alloy counterpart, the PtMn nanodendrite catalyst experiences less transition metals' dissolution in acidic solution and achieves an outstanding mass activity retention of 96 % after 10,000 degradation cycles. Density functional theory calculation reveals that PtMn alloys are thermodynamically more stable than PtNi alloys in terms of formation enthalpy and cohesive energy. The PtMn nanodendrite-based membrane electrode assembly delivers an outstanding peak power density of 1.36 W cm-2 at a low Pt loading and high-performance retention over 50 h operations at 0.6 V in H2 -O2 hydrogen fuel cells.

Applied Voltage‐Activated Fe─N─C Catalysts for Pem Fuel Cells

AbstractThe practical application of non‐precious Fe─N─C catalysts in proton exchange membrane fuel cells (PEMFCs) continues to remain one of the major challenges due to their relatively poor oxygen reduction reaction (ORR) performance in acid. In this work, a fast and facilely performance enhancement strategy is first proposed for various Fe─N─C catalysts by supplying different direct‐current voltages to achieve a rapid solid‐state activation at room temperature. The voltage‐activated state‐of‐the‐art Fe─N─C catalyst has demonstrated a peak power density of 1.1 W cm−2 for PEMFC and remarkably increased long‐term durability for ORR. The substantially improved performance can be attributed to the formation of highly active ketone‐decorated (edge‐hosted) FeN4 sites and substantially boosts coupled proton−electron transfer (CPET) by improving the conductivity of the as‐synthesized Fe─N─C with an interpenetrating network structure. The interconnected micro‐nodes within the interpenetrating network are the main active regions for the ORR, evidenced by an optimized structural model based on the above typical morphology. Therefore, this finding provides an innovative and facile idea for solving the activity and stability deficiency for promising Fe─N─C for commercial PEMFC.

A novel core-shell nanostructure of Ti-Au nanocrystal with PtNi alloy skin: Enhancing the durability for oxygen reduction reaction

The sluggish oxygen reduction reaction (ORR) at the cathode largely hinders the practical application of the proton-exchange membrane fuel cells (PEMFCs). Pt-based nanocrystals are the most effective electrocatalysts for the oxygen reduction reaction, however, suffer high cost, scarcity and unsatisfied durability. Herein, we report a new category of annealed multimetallic core-shell catalyst of gold core doped with titanium and platinum-nickel (PtNi) shell with Pt-rich surface as a highly active and robust electrocatalyst for ORR. The introduction of titanium can effectively stabilize the gold core, avoiding the outward migration of Au atoms and ensuring the exposure of Pt-Ni active sites. The experimental findings revealed that the annealed Ti-Au@PtNi NPs catalyst provides 19.26 and 9.84 times higher mass and specific activities than commercial Pt/C catalysts for the oxygen reduction reaction. Moreover, durability tests of annealed Ti-Au@PtNi NPs show no noticeable activity loss even after 20000 potential cycles between 0.6 and 1.0 V vs. RHE, demonstrating a promising catalyst for the oxygen reduction reaction.

In situ confined synthesis of an interlayer-riveted carbon shell encapsulated PdZnBi alloy as a highly active and durable oxygen reduction reaction catalyst

An interlayer riveted carbon shell encapsulated PdZnBi alloy is synthesized using the in situ confinement effect of small molecules. After a long-term durability test, its mass activity (MA) remained at 94% of the initial value.