Enhanced Hydrogen Evolution Research Articles

Constructing 2D PtSe2/PtCo Heterojunctions by Partial Selenization for Enhanced Hydrogen Evolution

AbstractThe rational design and fabrication of 2D heterojuctions are proven a promising strategy for boosting the performance of electrocatalysts. Although 2D platinum diselenide (PtSe2) exhibits catalytic activity for hydrogen evolution reaction (HER), the catalytic performance is still unsatisfactory due to its inert basal plane, wide bandgap, and poor electron transfer ability. Herein, a new strategy is reported to construct PtSe2/PtCo heterojunctions by partial selenization of PtCo alloy for high‐efficiency HER electrocatalyst, which exhibits a low overpotential of 38 mV at the current density of 10 mA cm−2, a small Tafel slope of 22 mV dec−1, and a superior stability over 24 h and 1000 cycles. The outstanding HER activity of the catalyst arises from the strong electronic interactions between PtSe2 and PtCo in the heterojunctions, which induce electron transferring from PtSe2 to PtCo and the d‐band center down shifting, and thus optimize the H* adsorption/desorption. This work provides a novel strategy for constructing highly efficient heterostructure electrocatalysts, which facilitates the applications of hydrogen energy conversion.

Copper-promoted growth of hierarchical Cu–Co–Ni alloys on copper nanodendrites for enhanced hydrogen evolution in a wide pH range

Efficient and sustainable electrocatalysts for the hydrogen evolution reaction (HER) using earth-abundant elements are crucial for eco-friendly hydrogen production, particularly under neutral and acidic conditions. In metallic alloys, careful selection of alloying elements and control over the composition, morphology, electronic structure, and structural defects are expected to tune electrocatalytic activities. In this work, we introduce a two-step electrodeposition approach to create a 3D porous trimetallic alloy, Cu@Cu–Ni–Co, exhibiting excellent catalytic activity and stability for HER in neutral and acidic environments. The process begins with the electrodeposition of 3D copper dendrites, which was found to be crucial for the catalyst's mechanical stability, followed by the deposition of the trimetallic alloy, where copper's inclusion promotes the controlled growth of the alloy's 3D structure. The Cu@Cu–Ni–Co catalyst outperforms Cu@Ni, Cu@Co, Cu@Ni–Co, and GC@Cu–Ni–Co electrocatalysts in neutral and acidic conditions, highlighting the importance of the developed electrodeposition approach. In 1.0 M phosphate-buffer solution (PBS), Cu@Cu–Ni–Co achieves a current density of 10 mA cm−2 at an overpotential of 275 mV with a Tafel slope of 134 mV dec−1, maintaining remarkable stability in both acidic and neutral conditions at high current densities (48–165 mA cm−2) for up to 50 h without any decline in activity.

Machine learning-assisted design of transition metal-doped 2D WSn₂N₄ electrocatalysts for enhanced hydrogen evolution reaction

Hydrogen energy is characterized as environmentally friendly and resourceful. The hydrogen evolution reaction (HER) is a crucial process for hydrogen production and is essential for achieving a transition to sustainable and clean energy. In this work, we conducted a systematic investigation into the hydrogen catalytic activity of two-dimensional WSn2N4 materials. The transition metal atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) were substituted at the N and Sn sites in WSn2N4, respectively. The catalyst's performance was evaluated to verify its catalytic activity for the HER. The results indicate that the Gibbs free energy changes (ΔGH∗) of Ti@W–WSn2N4, V@W–WSn2N4, Fe@W–WSn2N4, Co@W–WSn2N4, and Ni@W–WSn2N4 are close to zero. Among the structures examined, Ti@W–WSn2N4 exhibited the lowest Gibbs free energy change (ΔGH∗ = −0.01 eV), indicating a high degree of catalytic activity. Through machine learning analysis, key features affecting catalytic activity could be directly identified, and a framework for rapid screening was established. This study lays a solid foundation for the design and development of potential HER catalysts in the future.

In situ growth of Cd0.6Zn0.4S on graphene guided by ion anchoring for boosting hydrogen production

Owing to its large specific surface area and high conductivity, reduced graphene oxide (RGO) serves as an ideal platform for electron transfer. In this study, in situ growth of sulfides on RGO was attributed to metal ion anchoring on graphene oxide nanosheets by electrostatic attraction between negatively charged functional groups and metal ions. Tight binding between sulfides and RGO caused by in situ nucleation and growth can promote direct electron transfer and electron-hole separation, which is a more effective way to enhance hydrogen evolution activity. Cd0.6Zn0.4S/graphene (CZS/RGO) composite photocatalysts with different graphene ratios were prepared and exhibited high photocatalytic activity due to the improved dispersion of CZS and increased electronhole separation. The hydrogen production rate of CZS-0.8/RGO reached 52.50 mmol∙g–1∙h–1, and after nine cycles for 27 h, the hydrogen production efficiency remained at 86.4 %.

Enhancing hydrogen evolution: Carbon nanotubes as a scaffold for Mo2C deposition via magnetron sputtering and chemical vapor deposition

This study presents an innovative approach to fabricating carbon nanotubes (CNTs) through magnetron sputtering and chemical vapor deposition (CVD). These CNTs serve as a robust structural scaffold for the deposition of molybdenum, which, through thermal annealing, becomes molybdenum carbide (Mo2C), which is highly efficient for hydrogen evolution reaction (HER). Our investigation delves into the physical and chemical attributes of these electrodes, revealing insights into the functionality of Mo2C on CNTs hybrid structures. Chemical characterization confirms the exceptional performance of the electrode. Our Mo2C on CNT hybrid system showcases remarkable electrocatalytic activity, with an onset potential of 103 mV at 1 mA/cm2 and an overpotential of 176 mV at 10 mA/cm2. Further validation comes from tests revealing a Tafel slope of 95 mV/dec, affirming its superiority in facilitating HER. Unparalleled combination of low charge transfer resistance and accelerated reaction kinetics, Mo2C on CNTs hybrid structure is poised to significantly enhance HER activity.

Bimetallic MOF derived Cu3P/Co2P grown on coal-based carbon fibers as self-supporting electrocatalyst for enhanced hydrogen evolution

Transition metal phosphides (TMPs) are often considered as a cost-effective replacement for precious metal catalysts in hydrogen evolution reaction (HER). Herein, the fibers are produced by combining coal with electrospinning technology, and then undergoing a pre-oxidation process for transforming into pre-oxidized coal-based fibers. Subsequently, CuCo-metal organic framework (CuCo-MOF) is grown on the pre-oxidized coal-based fibers using solvothermal method, and the Cu3P/Co2P/coal-based carbon fibers (Cu3P/Co2P/C-CFs) composite catalyst is successfully fabricated by phosphating at low temperature and carbonizing at high temperature. The uniformly grown nanoparticles (NPs) on the surface of C-CFs enhance the electrochemically active area, while the electron transfer between Cu3P and Co2P effectively modulates the electronic structure, increasing the catalytic activity of the catalyst for HER. In addition, the flexible C-CFs not only serve as self-supporting electrode but also effectively inhibit the agglomeration of Cu3P/Co2P NPs. Remarkably, the overpotential of Cu3P/Co2P/C-CFs is 83 mV at 10 mA cm−2 current density for HER in 0.5 mol L−1 H2SO4 solution. This study presents promising strategies for the high value-added utilization of coal and the synthesis of highly effective non-precious metal catalysts.

Uncovering the electrochemical stability and corrosion reaction pathway of Mg (0001) surface: Insight from first-principles calculation

An understanding of the anomalously enhanced hydrogen evolution reaction (HER) of magnesium (Mg) under anodic polarisation in aqueous corrosion is paramount for a predictive theory of its corrosion and metal electrocatalysis. Previous theoretical and experimental studies have proposed that sub-surface hydride phases play a role in this behaviour but the underlying atomic mechanisms remain unclear. By constructing theoretical surface Pourbaix diagrams, based on density functional theory (DFT) calculations, we have identified the atomic structure of a sub-surface hydride phase on the Mg (0001) surface that remains electrochemically stable under significant anodic overpotentials across a wide pH range. Specifically, this stability persists up to 0.38 VSHE under mildly alkaline conditions (e.g., pH = 8), thus providing thermodynamic support for the proposed hydride-enhanced HER under anodic conditions. Reaction barrier analysis establishes that the proposed sub-surface hydride phase could promote anodic HER via a Heyrovsky pathway, based on hydrogen outward diffusion, with an energy barrier of 1.54 eV as the rate-limiting step, showing an anodic characteristic and significantly favouring external anodic polarisation. Furthermore, we have established that the surface adsorption condition, contingent on both the pH and potential, significantly influences the mechanism and kinetics of the initial corrosion of Mg.

Design of NiPS3/MoS2/rGO hybrid electrocatalyst for electrochemical hydrogen evolution

The design and development of efficient electrocatalysts for hydrogen evolution reaction is presently a pressing task to overcome future energy demands. In the present study a hybrid layered compound NiPS3/MoS2/rGO (NMR) is investigated as an electrocatalyst for hydrogen evolution reaction (HER). The metal trichalcogenidophosphates (MTPs), transition metal dichalcogenides and reduced graphene oxide materials based electrocatalysts are promising material for HER. The hybrid layered compound NMR displays good electrocatalytic activity in acidic medium in comparison to its counterparts MoS2/rGO and NiPS3/rGO with an overpotential and Tafel slope of 152 mV vs RHE and 75 mV/dec, whereas MoS2/rGO and NiPS3/rGO shows an overpotential of 206 mV and 223 mV vs RHE with a Tafel slope value of 146 mV/dec and 154 mV/dec respectively. The hybrid electrocatalyst exhibited high stability up to 1000 cycles with a stable current. The high HER activity of NMR is attributed to synergistic effect of electrocatalysts where P and S of NiPS3 acts as an appropriate hydrogen adsorption sites and catalytically active Mo edge sites of MoS2 with high charge carrier property of rGO contributed to enhanced hydrogen evolution reaction.

The significant role of Z-scheme band alignment at the heterojunction for the enhanced photocatalytic H2 production in TiO2/BiNbO4/rGO nanocomposite

An efficient ternary TiO2/BiNbO4/rGO nanocomposite was prepared by a simple wet impregnation process. PXRD confirmed the tetragonal and orthorhombic crystalline natures of titanium dioxide (TiO2) and bismuth niobate (BiNbO4) respectively. The loading of BiNbO4 and reduced graphene oxide (rGO) shifted the light absorption of TiO2 to a longer wavelength from 400 to 430 nm. The suitable conduction band position of BiNbO4 facilitated a favourable band alignment to suppress the electron/hole (e−/h+) recombination in TiO2 via the Z scheme mechanism at the heterojunction. The excited electrons at the CB of TiO2 were easily transported via the fast electron accepting and conducting rGO matrix for the surface redox reactions with the improved charge transfer efficiency, which was confirmed by EIS and PL studies respectively. BiNbO4 and rGO synergistically improved the specific surface area and solar light absorption. EPR analysis confirmed the presence of increased oxygen vacancies at the heterojunction. Hence, the ternary TiO2/BiNbO4/rGO nanocomposite demonstrated an enhanced hydrogen evolution (8910 μ mol h−1 gcat−1) than bare TiO2 (4820 μ mol h−1 gcat−1), bare BiNbO4 (950 μ mol h−1 gcat−1) and TiO2/BiNbO4 (6730 μ mol h−1 gcat−1) under direct solar light. The optimum of 1 wt % BiNbO4 and rGO loaded TiO2 nanocomposite produced twice the H2 production than the bare TiO2. This also further confirms that rGO played a major role during the photocatalytic process by highlighting the potential of metal oxides combined with carbon material as an efficient photocatalyst which prominently enhances the H2 evolution.

Harnessing the potential of MOF/Fe2O3 nanocomposite within polypyrrole matrix for enhanced hydrogen evolution

This study investigates the influence of pyrrole concentration and the addition of MIL53(Al)/Fe2O3 nanocomposite on the hydrogen evolution reaction (HER) activity of polypyrrole (PPy) electrocatalysts. Electrodeposition of PPy on a nickel (Ni) substrate was conducted using various pyrrole concentrations ranging from 0.01 M to 0.2 M, followed by evaluation through linear sweep voltammetry (LSV) experiments. Results indicated that PPy synthesized with 0.1 M pyrrole exhibited the highest HER activity, characterized by lower onset potential and higher current density. Additionally, the incorporation of MIL53(Al)/Fe2O3 nanocomposite into PPy coating enhanced electrode performance, evidenced by high charge transfer kinetics. Nyquist diagrams and electrochemical impedance spectroscopy (EIS) analysis confirmed accelerated electron transfer kinetics and lower charge transfer resistance for PPy@MIL53(Al)/Fe2O3 compared to Ni substrate. Despite a lower electrochemical double layer capacitance (Cdl), PPy@MIL53(Al)/Fe2O3 demonstrated enhanced catalytic activity, underscoring the importance of electrode morphology and active site characteristics. Furthermore, stability tests revealed consistent performance of PPy@MIL53(Al)/Fe2O3 over prolonged electrolysis periods, highlighting its potential for practical applications in hydrogen generation.

Accelerated Electrons Transfer and Synergistic Interplay of Co and Ge Atoms (111 Crystal Plane) Activated by Anchoring Nano Spinel Structure Co2GeO4 onto Carbon Cloth Composite Electrocatalyst for Highly Enhanced Hydrogen Evolution Reaction

The electrochemical hydrogen evolution reaction (HER) was considered to be a promising strategy for future clean energy. In this work, a composite electrocatalyst (designated as CGO36@CC) was synthesized through anchoring of nano spinel structure Co2GeO4 onto carbon cloth fibers and exhibited outstanding electrocatalytic performance for HERs in an alkaline medium. The characterization outcome established that, after 36 h of hydrothermal reaction, nano spinel structure Co2GeO4 particles (exposed abundant 111 crystal planes) were stably loaded onto a carbon cloth fiber surface, and this structural configuration facilitated the electrons transferring between each other. In addition, the electrochemical analysis revealed that the incorporation of nano spinel structure Co2GeO4 and carbon cloth significantly augmented the electrochemical activity value of the composite and efficiently enhanced the HER performance. Notably, the overpotential was merely 96 mV at 10 mA·cm−2 current density, and the Tafel slope was only 48.9 mV·dec−1. Moreover, CGO36@CC displayed remarkable catalytic activity and sustained HER catalytic stability. The theoretical catalytic prowess of CGO36@CC stemmed from the collaborative influence of germanium and cobalt atoms within the exposed 111 crystal plane of the Co2GeO4 molecular framework. The amalgamation of Co2GeO4 with carbon cloth fiber conferred upon the composite electrocatalyst both superior theoretical catalytic activity and enhanced electron transfer capability. This work provides a novel strategy for exploring a highly efficient composite electrocatalyst combined transition metal with carbon material to accelerate the HER activity.

Enhanced hydrogen evolution performance of twinned Mn0.65Cd0.35S with Zn-doped cadmium selenide under visible light irradiation

The cadmium manganese sulfide, despite being recognized as a highly efficient photocatalytic semiconductor for hydrogen evolution, faces significant challenges in terms of charge recombination when used solely as a catalyst for photocatalytic hydrogen production. The construction of heterojunction photocatalysts is regarded as one of the effective strategies to enhance the efficiency of photocatalytic hydrogen production. In this work, Zn-doped CdSe was adopted to enhance the photocatalytic active sites of the twinned Mn0.65Cd0.35S. As results, the photocatalytic hydrogen evolution of Zn–CdSe-1/T-MCS-40 can reach approximately 47447.15 μmol g−1 after 5 h, representing a 15 times increase compared to Mn0.65Cd0.35S. Besides, the hydrogen evolution rate shows almost no significant attenuation after four consecutive cycles (20 h). The significant achievement can be largely attributed to the successful construction of an S-scheme heterojunction of Zn–CdSe-1/T-MCS-40, which effectively minimized the charge transfer distance and suppressed the recombination of photo-generated electron-hole pairs. Additionally, the incorporation of Zn-doped CdSe significantly expands the response range to visible light, thereby providing a conceptual framework for advancing the design of solar-to-chemical energy conversion and effectively guiding the fabrication of metal sulfide-based photocatalytic heterojunctions.

Pristine Wood‐Supported Electrodes With Intrinsic Superhydrophilic/Superaerophobic Surface Intensify Hydrogen Evolution Reaction

AbstractWood, as a renewable material, has been regarded as an emerging substrate for self‐supporting electrodes in large‐scale water electrolysis due to numerous merits such as rich pore structure, abundant hydroxyl groups, etc. However, poor conductivity of wood can greatly suppress the performance of wood‐based electrodes. Carbonization process can improve wood's conductivity, but the loss of hydroxyl groups and the required high energy consumption are the drawbacks of such a process. Here, a facile strategy is developed to prepare pristine wood‐supported electrode (Ni‐NiP/W) for enhanced hydrogen evolution reaction (HER); this improves electrical conductivity of wood while retaining its excellent intrinsic properties. The preparation process involves the deposition of copper on the untreated wood followed with the loading of Ni‐NiP catalyst at room temperature. Encouragingly, the Ni‐NiP/W exhibits conductive and inherited pristine wood's superhydrophilic and superaerophobic properties, that effectively boost mass and charge transfer. It demonstrates high activity and excellent stability in acidic, alkali, and seawater conditions as well as high current densities of up to 2000 mA cm−2; particularly a record‐low HER overpotential of 206 mV in acidic conditions at 1000 mA cm−2. This work fully unlocks the admiring potential of pristine wood as superior substrate for high‐performance electrochemical electrodes.

Theoretical Prediction of Enhanced Hydrogen Evolution Reaction Electrocatalysts Based on Tantalum Phosphide.

Ta-based transition metal catalysts have shown significant catalytic activity for the hydrogen evolution reaction (HER) in recent studies. However, the application of tantalum phosphide (TaP) in the HER has not been documented. Herein, a systematic study of TaP catalysts was performed through density functional theory (DFT). The performance of TaP (004) for the HER was predicted. Thermodynamic analyses of Ta-terminated and P-terminated surfaces with adsorbed hydrogen atoms were conducted, and the HER mechanism on TaP (004) surfaces was carefully investigated. Theoretical results revealed that TaP (004) exhibits excellent HER activity (ΔGH* = 0.0456 eV), and both the Ta-terminated and P-terminated surfaces follow the Volmer-Heyrovsky mechanism under acidic conditions, with the Volmer step being the rate-determining step. A mixed surface strategy was also applied to explore the synergistic effects of Ta-terminated and P-terminated surfaces, which enhanced the HER activity. Additionally, the study screened dopants to assess their impact on the HER activity, revealing that doping with S, Ni, Co, Fe, and Cr could improve the HER performance.

Enhancing hydrogen evolution reaction performance through defect engineering in WTeX (X= S, Se) monolayers: A first-principles study

Finding a novel material to substitute the existing noble metal catalysts for the hydrogen evolution reaction (HER) is essential for the further advancement of water electrolysis technology. Herein, we investigated the feasibility of using defect engineering to improve the hydrogen evolution reaction (HER) catalytic performance of WTeX (X = Se, S) materials in the 2H, 1 T, and 1 T′ phases. The results demonstrate that the introduction of defects significantly enhances WTeX monolayers’ HER performance. As exemplary cases, the Gibbs free energy changes for 2H WTeSe with a Te vacancy (2H WTeSe–VTe) and 2H WTeS with a Te vacancy (2H WTeS–VTe) are 0.029 eV and −0.002 eV, respectively. It was found that the active sites in 2H WTeSe–VTe and 2H WTeS–VTe have a substantial number of empty anti-bonding states, which increases the bond strength between H and the catalyst, leading to exceptional catalytic performance. This work demonstrates the feasibility of defect-engineered WTeX structures as electrocatalysts and provides a reliable reference for the study of non-precious metal catalysts.

Highly porous Pt3Ni nanosheets for enhanced hydrogen evolution reaction

Two-dimensional (2D) nanosheets with high surface-to-volume ratios have garnered significant attention for their electrocatalytic properties. This study explores the characterization and electrocatalytic performance of highly porous monometallic platinum (Pt) nanosheets and bimetallic platinum-nickel (Pt3Ni) nanosheets for the hydrogen evolution reaction (HER) in both alkaline and acidic media. Advanced characterization techniques were employed to elucidate the morphological and compositional properties of the Pt and Pt3Ni nanosheets. Electrochemical characterization demonstrated that Pt3Ni nanosheets/C outperformed Pt nanosheets/C and commercial Pt/C in terms of HER activity and stability. The enhanced HER performance of Pt3Ni nanosheets/C is believed to be due to the dominance of the Volmer-Tafel mechanism. These findings highlight the potential of 2D bimetallic nanosheets and suggest a promising avenue for advancing hydrogen energy technologies.

Synergistic effects of 1T–2H MoS2 and laser-reduced graphene Oxide–ZnO scaffold composite catalyst for efficient hydrogen evolution reaction

A composite catalyst, zinc-doped laser-reduced graphene oxide (LrGO), is synthesized with highly dispersed molybdenum disulfide (MoS2) nanolayers using laser exfoliation followed by a hydrothermal process. The resultant LrGO–ZnO/1T–2H MoS2 (GZM3) catalyst exhibits enhanced hydrogen evolution reaction (HER) catalytic performance and improved stability. It achieves small overpotentials of 94 and 191.5 mV at a current density of 10 mA cm−2, under acidic and alkaline conditions, respectively. This superior catalytic activity is attributed to the high electrical conductivity and large electrochemical surface area of graphene, along with efficient charge transfer facilitated by Zn ions between LrGO–ZnO and 1T–2H MoS2.

Role of intrinsic point defects on electrocatalytic activity of a metal-free two-dimensional Polyaramid for enhanced hydrogen evolution reaction

Despite the current research aims at replacing expensive metals like Platinum with non-noble metals for producing hydrogen via hydrogen evolution reaction (HER), practical challenges like oxidation continue to be a significant concern. Our study aims at providing the metal-free alternative to such noble Pt-based catalysts. Taking care of the fact that the defects are inevitable during the material's growth process, we propose thermodynamically and thermally stable two-dimensional (2D) Polyaramid (2DPA) with possible intrinsic point defects as HER active materials with overpotentials comparable to that of Pt catalysts using density functional theory (DFT). Creating single carbon (VC), single nitrogen (VN), and single oxygen (VO) vacancies helps reducing its wide band gap upon creation of several defect states, thereby improving conductivity. VO-2DPA exhibits lowest ΔGH* value of −0.04 eV which is closest to thermoneutrality condition, i.e., ΔGH*≈0 while VN-2DPA is not found suitable for HER. The calculated low formation energies for generating point-vacancies under defect-poor growth conditions and the minimal bond length fluctuations within, serve as strong validation for the feasibility of their synthesis. Furthermore, underlying reaction mechanisms are also investigated for the HER process favouring the Heyrovsky reaction path over Tafel as the former requires lesser activation energy: 0.53 eV v. 0.86 eV for VC-2DPA and 0.34 eV v. 1.01 eV for VO-2DPA.

Interfacial Electronic Structure Engineering of NiCo2Se4 and NiTe2 Nanorods for Enhanced Hydrogen Evolution Reaction.

Finding the best candidates with outstanding electrocatalytic capabilities for the hydrogen evolution reaction is essential for realizing large-scale hydrogen production through electrolysis. In this study, we synthesized NiCo2Se4 (NCS) and NiTe2 (NT) nanorod arrays using a hydrothermal method. The confirmation of catalyst formation was achieved through X-ray diffraction analysis, electron microscopy imaging, and X-ray photoelectron spectroscopy. Leveraging the plentiful heterointerfaces and synergistic effects arising from the incorporation of bimetallic components, the NCS/NT electrocatalyst demonstrates remarkable efficacy in catalyzing the hydrogen evolution reaction. It achieves a minimal overpotential of 163 mV to attain a current density of 50 mA cm-2, showcasing exceptional catalytic activity. Further exploration has revealed that the engineering of heterogeneous interfaces and the morphology of nanorods not only guarantee the exposure of numerous active sites and expedite electron-mass transfer but also trigger electron modulation. Such modulation serves to fine-tune the adsorptive and adsorptive dynamics of reaction intermediates, culminating in an enhancement of the catalyst's inherent activity. This study illuminates the novel composite electrocatalyst with robust synergy, highlighting the pivotal role of their unique nanostructures in achieving high-efficiency hydrogen production via electrolysis.

Synergistic effect of Bi and Fe for suppressing hydrogen evolution reaction (HER) and enhancing electrochemical nitrogen reduction reaction (eNRR) performance

The electrochemical nitrogen reduction reaction (eNRR) displays significant potential for the synthesis of ammonia. However, eNRR electrocatalysts with high catalytic activity and selectivity still need to be developed. In this study, a Bi-doped La0.9Bi0.1FeO3-δ (LBiF) perovskite was fabricated as a potential cathode catalyst and incorporated into a protonic ceramic electrolysis cell (PCEC) for eNRR. Electrochemical tests demonstrated that the LBiF cathode reveals higher eNRR catalytic activity and enhanced hydrogen evolution reaction (HER) inhibition compared to undoped LaFeO3 (LF). Characterization of the LBiF cathode following 90 h of NH3 synthesis revealed surface reconstruction of the catalyst during eNRR. Particularly, Bi3+ is partially reduced to Bi2+ and metallic Bi, resulting in A-site defects and an increased concentration of oxygen vacancies (OVs) and Fe4+ in accordance with the charge neutrality principle. Both the OVs and Fe4+ can accept electron pairs provided by N2 due to their unsaturated electronic structures. Furthermore, Bi doping inhibits the HER because Bi preferentially binds to N instead of H. Bi doping creates new Bi3+/Bi2+/Bi0 redox electron pairs, establishing an electron transfer path that improves perovskite conductivity and eNRR electrocatalytic activity. This study sets a foundation for designing eNRR catalysts aimed at suppressing the HER.