Enhanced Oxygen Reduction Reaction Research Articles

Phase engineering of Pt-Mn intermetallics for durable oxygen reduction reaction electrocatalysis

Controlling the crystal phase of intermetallic has been demonstrated as a promising strategy for enhancing oxygen reduction reaction (ORR) performance. However, the controlled synthesis of intermetallic with specific crystal phases remains a formidable challenge. Herein, structure ordered Pt-Mn intermetallics with face-centered cubic Pt3Mn (fcc-Pt3Mn/C) and face-centered tetragonal PtMn (fct-PtMn/C) are synthesized via an impregnation-reduction method. Benefiting from the rational control of crystal phase, fct-PtMn/C with optimal surface atomic arrangement and binding environment exhibits higher activity than fcc-Pt3Mn/C and Pt/C. Moreover, fct-PtMn/C exhibits a superior mass activity retention rate of 90.3 % after 50,000 potential cycles from 0.6 to 1.0 V compared to significantly lower rate of 56.0 % and 34.8 % for fcc-Pt3Mn/C and Pt/C, respectively. Structural analysis reveals that fct-PtMn/C maintains its crystal phase, particle size, and morphology exceptionally well during the durability test, demonstrating its outstanding structural stability. Theoretical calculations indicate that phase engineering can lower the reaction energy barrier, weaken the adsorption energy of reaction intermediates on fct-PtMn/C, and thus enhance the ORR performance.

Enhancing oxygen reduction reaction with Pt-decorated Cu@Pd and high-entropy alloy catalysts: Insights from first-principles analysis of Pt arrangement

The efficiency of oxygen reduction reaction (ORR) in the proton-exchange membrane fuel cells (PEMFCs) heavily relies on the surface Pt atom arrangement, which can be represented by the Pt-Pt average distance. Here, we employed density functional theory (DFT) to examine the influence of Pt arrangement on the ORR efficiency of Cu@Pd core-shell and high-entropy alloy catalysts. Our DFT calculations reveal that a shorter Pt-Pt average distance on the surface leads to a lower O2 dissociation barrier. Nevertheless, a shorter Pt-Pt average distance is not thermodynamically favored for the Cu@Pt catalyst. Moreover, we discovered a robust correlation between the level of the d-band center of the catalyst and the O2 adsorption energy. To explore the potential of controlling Pt arrangement, we investigated the use of NbMoTaW high-entropy alloy (HEA) substrates. Our findings suggest that HEA substrates provide promising surface chemistry for tuning Pt arrangement and controlling the O2 dissociation barrier.

Sulfur atom modulated Fe-Nx species embedded in hollow porous carbon spheres for efficient oxygen reduction and high-performance zinc-air batteries

A nitrogen (N) and sulfur (S) co-doped FeS/FeN-NC-X4 (X represents the molar ratio of Fe and S added) catalyst with an abundant S-doped Fe-Nx species is designed rationally for enhanced oxygen reduction reaction (ORR). And these valuable activation sites are embedded into a hollow porous carbon shell for increasing the limiting current density and increasing the onset potential. The precise regulation of the Fe/S ratio also highlights the influence of appropriate S doping on the catalytic performance of atomically dispersed Fe–N–C-based catalysts for high-performance Zinc-air batteries. All of these factors contribute to the remarkable catalytic performance of FeS/FeN-NC-X4 for the ORR with a half-wave potential of 0.863 V, which is superior to most non-precious metal catalysts previously reported. Simultaneously, the synthesized material is used as a cathode catalyst to assemble zinc-air batteries to illustrate its practical application. The results show that it has a high open-circuit voltage (1.44 V), extremely high maximum power density (156 mW cm−2) and excellent stability (stable operation for 400 h at a current density of 5 mA cm−2). The assembled portable and flexible batteries also have a high open circuit voltage of 1.40 V and a maximum power density of 68.1 mW cm−2. This work therefore presents a new method for the synthesis of atomically dispersed iron catalysts with high efficiency and metal content that are appropriate for practical energy storage applications.

Fine-Tuning Dual Single-Atom Metal Sites on Graphene toward Enhanced Oxygen Reduction Reaction Activity.

The oxygen reduction reaction (ORR) remains at the forefront of research in diverse energy and sustainability domains. While graphene-supported single-atom catalysts (SACs) have garnered attention for optimizing ORR efficiency, tailoring the interactions between adjacent single-atom sites presents intricate challenges. In this study, we leveraged density functional theory (DFT) calculations and cutting-edge machine learning (ML) techniques to explore 144 graphene-supported SACs, featuring interacting M1-N4 and M2-N4 moieties (M1, M2 = Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag Ir, Pt, Au), denoted as M1-M2. By tailoring these interactions, we discovered 13 exceptional SACs outperforming the benchmark catalyst Fe(OH)-N4, including the best-performing Fe-Pd and several non-noble-metal SACs like Fe-Ag, Ag-Cu, and Ag-Ag. Venturing further, our ML models effectively capture the correlation between single-atom metal properties and overpotential, offering tools for rational electrocatalyst design. Our study illuminates the path to efficient SAC-catalyzed ORR, fostering a sustainable, energy-efficient future.

Atomic-Level Regulation of Cu-Based Electrocatalyst for Enhancing Oxygen Reduction Reaction: From Single Atoms to Polymetallic Active Sites.

The slow kinetics of cathodic oxygen reduction reactions (ORR) in fuel cells and the high cost of commercial Pt-based catalysts limit their large-scale application. Cu-based single-atom catalysts (SACs) have received increasing attention as a promising ORR catalyst due to their high atom utilization, high thermodynamic activity, adjustable electronic structure, and low cost. Herein, the recent research progress of Cu-based catalysts is reviewed from single atom to polymetallic active sites for ORR. First, the design and synthesis method of Cu-based SACs are summarized. Then the atomic-level structure regulation strategy of Cu-based catalyst is proposed to improve the ORR performance. The different ORR catalytic mechanism based on the different Cu active sites is further revealed. Finally, the design principle of high-performance Cu-based SACs is proposed for ORR and the opportunities and challenges are further prospected.

Cerium oxide boosted CoFe-N codoped carbon nanotubes with abundant oxygen-vacancies toward efficient oxygen reduction and methanol oxidation reaction

In this study, we designed a novel strategy that utilizes N-doped carbon nanotubes as the chemical bond supporter to stabilize ultrafine CoFe alloy and introduces secondary CeO2 active sites into the hybrid, resulting in the formation of CeO2/CoFe-NCNTs heterostructures with exceptional bifunctional electrocatalytic capabilities. To be specific, solution dispersion and high-temperature calcination methods were employed to create the CoFe-NCNTs active sites through the introduction of ethylenediamine into the network interstitials of Co-EDTA and Fe-EDTA. The CeO2/CoFe-NCNTs hybrid not only promotes oxygen absorption and conversion of intermediates, but also accelerates charge transfer capability, thus enhancing oxygen reduction reaction (ORR) performance, while simultaneously inducing boosted the methanol oxidation reaction (MOR) activity. Moreover, the well-dispersed CoFe nanoparticles within the hybrid hold significant potential for establishing metal-nitrogen bonds with the N-doped carbon nanotube network, resulting in efficient catalytic behavior driven by synergistic effects with CeO2 nanoparticles, which contributes to reactant activation. As expected, the resultant CeO2/CoFe-NCNTs-2 exhibits remarkable electrocatalytic performance, with a current density of 281.40 mA cm−2 at a scan rate of 200 mV s−1 and a low Tafel slope (71.3 mV dec−1) for MOR, as well as achieving excellent half-wave potential and onset potential values of 0.834 and 0.90 V (vs. RHE) for ORR. Additionally, it exhibits durable cycle stability for both MOR and ORR, retaining 92.8% and 96.4% of its initial current density during the I-t test, respectively. This work establishes a highly efficient bifunctional earth-abundant electrocatalysts for both anode and cathode reactions in methanol fuel cells.

Tuning the Bonding Behavior of d‐p Orbitals to Enhance Oxygen Reduction through Push–Pull Electronic Effects

AbstractThe regulation of electronic structure is intricately linked to the intrinsic activity of oxygen reduction. Herein, a strategy for electronic structure modulation induced by bimetallic push–pull electronic effects in dual‐atom catalysts (Fe,Ni/N‐C@NG) is developed. Experiments and theoretical analysis reveal that Fe sites exhibit favorable bonding behaviors (Fe–O: dxz‐p, dyz‐p, and dz2‐p) and spin configurations, which can enable rapid desorption of *OH and thus enhance the intrinsic activity of oxygen reduction. In situ monitoring techniques and Gibbs free energy diagram further demonstrate that the adjacent Ni could serve as second active center to participate in oxygen reduction. The Fe,Ni/N‐C@NG exhibits enhanced oxygen reduction reaction activity and excellent stability. Meanwhile, the assembled Zn–air battery maintains stability for over 300 h with a small voltage gap. This study provides multiple insights into the orbital scale laws of oxygen reduction.

Carbon nanotube supported zinc, cobalt, nitrogen, sulfur-doped porous carbon as electrocatalyst for enhanced oxygen reduction reaction

Carbon nanotube (CNT) supported zinc, cobalt, nitrogen, sulfur-doped porous carbon (CNT@ZnCo/NSC) catalysts are prepared by in situ growth of sulfur-containing bimetal zeolitic imidazolate framework (S–ZnCo-ZIF) polyhedrons on CNT with subsequent heat treatment. The microstructure, morphology, particle size distribution, specific surface area, and pore-size distribution of the catalysts are characterized by multiple techniques. CNT@ZnCo/NSC exhibits excellent catalytic activity for oxygen reduction reaction (ORR) with onset potential of 0.98 V and half-wave potential of 0.83 V, respectively, which are close to those of Pt/C. The addition of CNT inhibits the agglomeration and improves the conductivity of the catalysts, while S doping enhances the electrochemical surface area and introduces active sites. The special structure makes CNT@ZnCo/NSC possess proper specific surface area (390.8 m2 g−1) and large average pore size (5.26 nm). CNT@ZnCo/NSC contains more graphite-N (21%) and pyridine-N (55.9%) than CNT@ZnCo/NC (20%, 46.5%) and ZnCo/NC (8.2%, 45.8%). CNT@ZnCo/NSC catalyst has better methanol tolerance and long-term stability than commercial Pt/C.

Elucidating the roles of oxygen defects-rich TiOxNy shell in Ti-based electrocatalyst for enhanced oxygen reduction reaction

Ti-based materials are among the most widely studied catalysts for the oxygen reduction reaction (ORR). However, the actual roles of the catalytically active sites in N-doped Ti-based electrocatalysts are still unclear. In this work, TiO2 and TiN were used as the precursors for the thermal nitridation and oxidation reactions at high temperatures, respectively. Titanium oxynitride (TiOxNy) species with abundant oxygen defects, formed on the surface of the as-prepared catalysts, were found to play an essential role to achieve the uniform distribution of ultrafine Pt nanoparticles via atomic layer deposition, thereby enhancing the ORR performance. The TiN-supported Pt catalyst showed excellent ORR performance and stability in acidic conditions, with an onset potential of 0.88 V and a half-wave potential of 0.76 V (vs. RHE). The catalyst also delivered a mass activity of 112 A gPt−1, which is 1.9 times higher than that of commercial Pt/C. A combination of experiments and characterizations confirmed that the synergistic effects between the outer TiOxNy shell with abundant oxygen defects and the high-conductivity TiN core contribute to the enhanced ORR performance. The present work sheds light on the essential roles of oxygen defect-rich TiOxNy species in Ti-based electrocatalysts.

Fabrication of Low-Temperature Solid Oxide Fuel Cells via Development of Magnetron Sputtering Process

We herein report the development of the sputtering process for the fabrication of thin film low-temperature solid oxide fuell cells (LT-SOFCs) supported by anodized aluminum oxide (AAO). The process development has been conducted for each component, anode, electrolyte, electrolyte/cathode interlayer, and cathode to achieve not only high performance but also durability. In order to fabricate catalyst-ion conducting anode cermet, Ni and GdCe co-sputtering is utilized. Since the AAO is an electrical insulator, the electrons produced from the anode requires to pass through the thin anode layer to be collected which can lead to high current collecting resistance. Therefore, sputtering conditions such as power, pressure, and time are adjusted to produce the anode with minimal ohmic loss stemming from current collection. For the electrolyte (YSZ) and interlayer (GDC), a ceramic sputtering recipe has been developed to achieve high density and uniformity, which are the most critical requirement for these components. Through optimization of the gun angle, power, pressure, and the target to substrate distance (TSD), a highly dense and uniform ceramic electrolyte can be deposited on various AAO substrate sizes. For the cathode, a mixed ionic electronic conducting cathode sputtering recipe has been developed to enhance oxygen reduction reaction (ORR) at low operating temperatures. We have been developing the sputtering process to fabricate a nanocrystalline and highly porous LSC-GDC cathode with desired microstructure to enhance the ORR activity. Through the integration of the aforementioned sputtering process development, durable and high performance LT-SOFCs have been successfully fabricated on AAO substrates up to 15cm x 15cm size. Suppered thin film cells have shown superior performance at low operating temperatures, e.g., peak power density of 1.5W/cm2 at 550oC with hydrogen fuel.

Tuning the Pt-N coordination in Pt/MOFs nanosheets under N2 plasma for enhanced oxygen reduction reaction

Regulation of the local coordination of metal sites can tune the electronic structure of catalysts, thereby improving electrocatalytic activity and reaction selectivity. This study proposes a strategy for designing highly active catalysts by regulating Pt-N coordination through N2 plasma treatment. Zn-BDC (1,4-benzenedicarboxylic acid) nanosheets embedded with Pt nanoparticles (Pt/Zn-BDC) were successfully fabricated. Subsequently, radio frequency (RF) discharge N2 plasma was applied to tune the Pt sites of Pt/Zn-BDC at room temperature. The plasma-treated Pt/Zn-BDC showed enhanced catalytic activity for the oxygen reduction reaction (ORR) with a high half-wave potential (0.835 V), superior to those of pristine Pt/Zn-BDC and 20 wt% Pt/C. Notably, rechargeable Zn-air batteries based on plasma-treated catalysts were demonstrated to exhibit high efficiency and stability. The enhanced catalytic performance originated from the optimized coordination environment and electronic structure of the Pt sites under N2 plasma treatment. This study provides a facile, green method of regulating promising ORR electrocatalysts via low-temperature plasma treatment.

Sr3Fe1.5Zn0.5O7-δ as Cathode for Protonic-Conducting Solid Oxide Fuel Cells with Enhanced Oxygen Reduction Reaction Activity

Common concerns about green energy have led to a wide focus on solid oxide fuel cells (SOFCs) for their environmental friendship and high efficiency. As the most popular electrode, perovskite materials feature the flexible structure and abundant oxygen sites, which correspondingly leads to diverse doping strategies and good electrochemical performance. However, the high operating temperature results in hot corrosion of both cells and encapsulating materials. Operating under various atmospheres, the generated impurities also cause a measure of irreversible degradation. Here, we first introduced Zn to Sr3Fe2O7-δ perovskite cathode in protonic ceramic fuel cells (PCFCs). Ruddlesden-Popper oxides Sr3Fe2-xZnxO7-δ (SFZx, x=0, 0.1, 0.5) were successfully synthesized and exhibited great performance under intermediate temperatures. The polarization resistance is 0.072 Ω·cm-2 which is 47% lower than that of the undoped Sr3Fe2O7-δ, and the maximum peak power density of the single-cell of NiO-BaZr0.1Ce0.7Y0.2O3- δ(BZCY)|BZCY|SFZ05 reaches 523.56 mW·cm-2 at 750℃, increased by 22%. The improvement is attributed to the formation of oxygen vacancies and the larger triple-phase boundary areas. Furthermore, the electrochemical impedance spectra (EIS) and distribution of relaxation time (DRT) results manifest that the rate-limiting steps are accelerated charge transfer and ionic migration processes. Finally, SFZ05 also presented better CO2 tolerance under an atmosphere of 5% CO2/air. These results display that SFZ05 is a promising candidate for a highly active and stable cathode for PCFCs.

Enhanced oxygen reduction reaction catalyst stability and durability of MXene-supported Fe-N-C catalyst for proton exchange membrane fuel cell application

The wide application of proton exchange membrane fuel cells (PEMFCs) is hindered by their slow oxygen reduction reaction (ORR) at the cathode. To increase their practicality and economic viability, non-noble metal catalysts are developed to boost the cathodic reaction. However, they exhibit lower activity than noble metal catalysts and suffer from durability issues. In this study, multilayer Ti3C2Tx MXene is used as the catalyst support for a non-noble metal Fe-N-C catalyst for ORR. Fe-N-C is synthesized by doping Fe ions into a zeolitic imidazole framework (ZIF-8) precursor. MXene is introduced after the first pyrolysis with different mass ratios. A second pyrolysis heat treatment is employed to optimize the catalyst activity and stability. The optimized Fe-N-C/Ti3C2Tx-(4:1)− 500 composite catalyst demonstrates higher ORR activity (Eonset = 0.88 V vs. RHE) than Fe-N-C (Eonset = 0.83 V vs. RHE) catalyst. Its stability is better than commercial Pt/C for over 10,000 s based on a chronoamperometry test. More than 94% of the current remains after 10,000 s for the composite catalyst, while Pt/C only retains 61%. The durability investigation involving load cycle and start-stop cycle protocols further substantiates the durability of the Fe-N-C/Ti3C2Tx-(4:1)− 500 catalyst for ORR. In addition, the use of Ti3C2Tx MXene as the catalyst support for Fe-N-C improves PEMFC performance with an 80.8% increment in power density compared to that without MXene support.

Facile fabrication of Mn-N doped porous carbon nanocages with enhanced oxygen reduction reaction activity

Mn-based oxygen reduction reaction (ORR) catalysts have high expectations, but cost and stability have always been the key problems to be solved in their industrialization. Herein, a novel electrocatalyst consisted of Mn-Nx doping sites within carbon frameworks was fabricated through a simple thermal and pickling treatment. The catalyst showed well-defined nanocage structure and excellent ORR performance with a half-wave potential of 0.85 V and a current density of 6 mA cm−2 -- these values are comparable to most Mn-based catalysts and commercial Pt/C. The unique advantages of the catalyst are facile procedure, low cost and good stability. The activities of the possible active sites in Mn-NPC (N doped porous carbon) were compared using theoretical calculations and recent experimental evidence, and the results showed that Mn-N5 moiety has lower free energy barrier and higher oxygen adsorption performance than Mn-N4 and Mn-N3 moieties to accelerate the ORR kinetics, which is of great significance for the subsequent design and directional synthesis of Mn-based catalysts.

DFT-guided design and synthesis of sea cucumber-derived N, S dual-doped porous carbon catalyst for enhanced oxygen reduction reaction and Zn-air battery performance

DFT-guided design and synthesis of sea cucumber-derived N, S dual-doped porous carbon catalyst for enhanced oxygen reduction reaction and Zn-air battery performance

A general strategy for direct growth of yolk-shell MOF-on-MOF hybrids

Construction of metal–organic framework (MOF) hybrids with yolk-shell nanostructures via MOF-on-MOF growth is significant for MOF design toward elaborate properties and enhanced performances, while remains challenging. Here, we report the direct growth of yolk-shell MOF-on-MOF hybrids via an interfacial growth-reorganization strategy. The synthesis relies on the precise growth of guest CoZn-ZIF (ZIF = zeolite imidazole framework) with appropriate crystal diameter and arrangement on host MOFs, inducing an in-situ transformation of core–shell intermediate into yolk-shell product. This strategy can be generally applied to the growth of CoZn-ZIF onto various host MOFs with different shapes, crystal structures and compositions including rod-like and octahedral Fe-based NH2-MIL-88B (MIL = Material Institute Lavoisier) and cake-like Ti-based NH2-MIL-125 toward three kinds of yolk-shell MOF-on-MOF hybrids. Moreover, functional carbon materials with bridged yolk-shell architecture can be prepared by pyrolysis of MOF-on-MOF hybrids as precursors, exhibiting enhanced oxygen reduction reaction performance than their monomeric counterparts. Our work paves the way for the design and application of MOF based yolk-shell nanostructures.

Graphitic carbon nitride immobilisation on graphene sheets for enhanced oxygen reduction reaction and poison tolerant cathode catalyst in microbial fuel cell

This investigation evaluated the efficacy of microbial fuel cell (MFC) employing cathode catalysed with reduced graphene oxide embedded on graphitic carbon nitride nanocomposite. The catalyst showed an excellent electrochemical response with a minimal charge transfer resistance of 11.5 Ω, compared to the conventional Pt/C (10.1 Ω). The physicochemical characterisation exhibited the existence of graphitic, pyridinic and pyrrolic N, which can accelerate oxygen reduction reaction. The MFC using cathode catalysed with graphitic carbon nitride supported over reduced graphene oxide (rGO-GCN) nanocomposite showcased an excellent performance with 15.72 W/m3 of maximum power density, 84.10% of organic matter removal, and 33.75% of coulombic efficiency that was superior to MFC using Pt/C catalysed cathode (26.94%). Additionally, the poisoning test of rGO-GCN catalyst showed 1.33-times more relative current when poised with a 3 mM concentration of S2-. The results of this investigation revealed that the synthesised catalyst is suitable for field-scale applications with 26-folds lower synthesis cost (1.24 $/g) compared to commercial Pt/C.

Mitigating Co Metal Particle Agglomeration and Enhancing ORR Catalytic Activity through Nitrogen-Enriched Porous Carbon Derived from Biomass

Biomass-derived porous carbon has gained significant attention as a cost-effective and sustainable material in non-noble metal carbon-based electrocatalysts for the oxygen reduction reaction (ORR). However, during the preparation of transition metal catalysts based on biomass-derived porous carbon, the agglomeration of transition metal atoms often occurs, leading to a notable decline in catalytic activity. In this study, we present a straightforward synthetic approach for the preparation of nitrogen-enriched soybean-derived porous carbon (Co@SP-C-a) as an electrocatalyst for the ORR. To achieve this, we employed a two-step method. In the first step, a chemical activator (KCl) was utilized to enhance the porosity of the self-doped nitrogen biomass carbon material. In the second step, a constant pressure drop funnel technique was employed to uniformly disperse bimetal cobalt/zinc-based zeolitic imidazolium frameworks (ZIF-L and ZIF-67) containing different metal ions (Zn2+ and Co2+) into the activated biomass carbon material. Subsequent high-temperature calcination of the ZIF-L and ZIF-67@SP-C-a composite precursor yielded the Co@SP-C-a catalyst. The obtained catalyst exhibited remarkable ORR activity in an alkaline solution (Eonset = 0.89 V, E1/2 = 0.83 V, JL = −6.13 mA·cm−2) and exceptional long-term stability. This study presents an effective strategy to prevent the agglomeration of metal nanoparticles when integrating them with biomass-based carbon materials, thus leading to enhanced catalytic performance.

Fe2O3/Fe/Fe-N multidimensional cross-linked composite enhancing oxygen reduction reaction of al-air batteries: Oxygen vacancies and bandgap engineering

Surface oxygen vacancy increases active site numbers, and multidimensional cross-linked structure improves the exposure of active sites. Thereby, they can enhance the oxygen reduction reaction (ORR) performance of Fe-N-C catalysts effectively. Herein, Fe(NO3)3·9H2O and carbon nanotubes (CNTs) were introduced into zeolitic imidazolate framework nano leaves (ZIF-L) to prepare multidimensional cross-linked Fe-N-CNTs with surface oxygen vacancies through co-pyrolysis at the high-temperature. As expected, the synthesized multidimensional cross-linked Fe-N-CNTs-900-0.2 composite rich in oxygen vacancies increased the conduction band potential and improved the reducing capacity. Thus, Fe-N-CNTs-900-0.2 possessed a better ORR electrochemical performance (half-wave potential = 0.892 V vs. RHE) that surpass the Pt/C catalysts. Moreover, the Al-air batteries containing Fe-N-CNTs-900-0.2 displayed a higher maximum power density than those of Pt/C catalysts. The electronic band structure shows that Fe-N-CNTs-900-0.2 rich in oxygen vacancy concentration has higher conduction band potential and effectively improves the activity of ORR catalysts. This work innovatively proposes that the joint work of multidimensional cross-linked structure and oxygen defects is an effective method to enhance the ORR performance and clarifies its internal reaction mechanism, which provides a new idea to design and preparer Fe-N-C catalysts.

Enhanced oxygen reduction reaction activity and electrochemical performance of A-site deficient (La0.6Sr0.4)1-xFe0.8Ni0.2O3−δ cathode for solid oxide fuel cells

In this work, (La0.6Sr0.4)0.9Fe0.8Ni0.2O3-δ (LSFN90), a stable, highly ORR-active and cost-efficient perovskite oxide, is developed as cathode materials for solid oxide fuel cell (SOFC). The introduction of A-site deficiency results in the crystal expansion of the cubic perovskite phase and an increase in oxygen vacancy concentration at operating temperature. The LSFN90 cathode displays good oxygen reduction reaction activity and low polarization resistance values. The A-site deficiency facilitates the diffusion of oxygen ions in the electrode and accelerates the surface oxygen exchange reaction. LSFN90 is used as cathode materials for SOFC to prepare anode-supported single cells, achieving maximum power densities of 1.51, 1.27, 0.95 and 0.63 W cm−2 under wet hydrogen (3%H2O–97%H2) atmosphere at 850, 800, 750 and 700 °C, respectively. The introduction of A-site deficiency can greatly enhance the oxygen reduction reaction activity and electrochemical performance of the cathode, demonstrating that LSFN90 has significant potential as a cathode material for practical applications in solid oxide fuel cells.