Ir Nanoparticles Research Articles

Unearthing Atomic Dynamics in Nanocatalysts.

Being able to access the rich atomic-scale phenomenology, which occurs during the reactions pathways, is a pressing need toward the pursued knowledge-based design of more efficient nanocatalysts, precisely tailored atom by atom for each reaction. However, to reach this goal of achieving maximum optimization, it is mandatory, first, to address how exposure to the experimental conditions, which will be needed to activate the processes, affects the internal configuration of the nanoparticles at the atomic level. In particular, the most critical experimental parameter is probably the temperature, which among other unwanted effects can induce nanocatalyst aggregation. This work highlights the high potential of experimental techniques such as the scanning probe microscopies, which are able to investigate matter in real space with atomic resolution, to reach the key challenge in heterogeneous catalysis of achieving access to the atomic-scale processes taking place in the nanocatalysts. Specifically, the phenomenology occurring in a nanoparticle system during annealing is studied with atomic precision by scanning tunneling microscopy. As a result, the existence of an internal atomic restructuring, occurring already at relatively low temperatures, within Ir nanoparticles grown over h-BN/Ru(0001) surfaces is demonstrated. Such restructuration, which reduces the undercoordination of the outer Ir atoms, is expected to have a significant effect on the reactivity of the nanoparticles. Going a step further, an internal restructuring of the nanoparticles during their involvement as catalysts has also been also identified.

Copper single atoms decorated iridium nanoparticles for the selective hydrogenation of bromonitrobenzene

The interaction between metals is an important factor to modify the catalytic roles of metallic catalysts, and it is highly desirable to reveal the relationship between metal-metal interaction and catalytic performance. Three types of Ir-Cu catalysts including Cu single atoms modified Ir nanoparticles and Ir-Cu alloy catalysts are prepared to observe the modifying role of Cu on Ir. Under relatively high temperature treatment, Ir-Cu alloy can be produced from Cu single atoms and Ir nanoparticles. The selectivity to bromoaniline (BAN) over Cu/C-Ir catalyst can be up to 99.9 % at the 100 % conversion of bromonitrobenzene (BNB), which is higher than that over Ir/C (94.3 %) and Ir-Cu/C alloy catalyst (98.5 %). The turnover frequencies (TOFs) of Cu/C-Ir catalysts are evidently lower than that of the Ir-Cu/C alloy catalyst, though their dispersions are higher than that of Ir-Cu/C alloy catalyst. The electronic transfer from Cu single atoms to Ir nanoparticles not only weakens the hydrogen adsorption ability but reduces the number of active sites available for splitting hydrogen molecules into hydrogen atoms, leading to a decrease in the catalytic activity for the selective hydrogenation of BNB. The interaction exerted by unalloyed Cu single atoms on Ir nanoparticles differs from that of alloyed Cu on Ir, which may be the possible reason for the different catalytic performance between Cu single atoms modified Ir nanoparticles and Ir-Cu alloy.

Monitoring the Structural Changes in Iridium Nanoparticles during Oxygen Evolution Electrocatalysis with Operando X-ray Total Scattering.

Understanding the structure of nanoparticles under (electro)catalytic operating conditions is crucial for uncovering structure-property relationships. By combining operando X-ray total scattering and pair distribution function analysis with operando small-angle X-ray scattering (SAXS), we obtained comprehensive structural information on ultrasmall (<3 nm) iridium nanoparticles and tracked their changes during oxygen evolution reaction (OER) in acid. When subjected to electrochemical conditions at reducing potentials, the metallic Ir nanoparticles are found to be decahedral. The iridium oxide formed in the electrochemical oxidation contains small rutile-like clusters composed of edge- and corner-connected [IrO6] octahedra of a very confined range. These rutile domains are smaller than 1 nm. Combined with complementary SAXS data analysis to extract the particle size, we find that the OER-active iridium oxide phase lacks crystalline order. Additionally, we observe an iridium oxide contraction under OER conditions, which is confirmed by operando X-ray absorption spectroscopy. Our results highlight the need for multitechnique operando studies for a complete understanding of the electrochemically formed Ir oxide active in OER.

Scalable Solid-State Synthesis of Carbon-Supported Ir Electrocatalysts for Acidic Oxygen Evolution Reaction: Exploring the Structure-Activity Relationship.

Enhancing iridium (Ir)-based electrocatalysts to achieve high activity and robust durability for the oxygen evolution reaction (OER) in acidic environments has been an ongoing mission in the commercialization of proton exchange membrane (PEM) electrolyzers. In this study, we present the synthesis of carbon-supported Ir nanoparticles (NPs) using a modified impregnation method followed by solid-state reduction, with Ir loadings of 20 and 40 wt % on carbon. Among the catalysts, the sample with an Ir loading of 20 wt % synthesized at 1000 °C with a heating rate of 300 °C/h demonstrated the highest mass-normalized OER performance of 1209 A gIr-1 and an OER current retention of 80% after 1000 cycles of cyclic voltammetry (CV). High-resolution STEM images confirmed the uniform dispersion of NPs, with diameters of 1.6 ± 0.4 nm across the support. XPS analysis revealed that the C-O and C═O peaks shifted slightly toward higher binding energies for the best-performing catalyst. In comparison, the metallic Ir state shifted toward lower binding energies compared to other samples. This suggests electron transfer from the carbon support to the Ir NPs, indicating a potential interaction between the catalyst and the support. This work underscores the strong potential of the solid-state method for the scalable synthesis of supported Ir catalysts.

Low Ir-Containing Materials As Anode Catalysts for PEM Water Electrolysis

The PEM electrolysis is based on the application of IrO2 as anode catalyst. Until now, there is no real alternative for this electrocatalyst, since the highly acidic and oxidative conditions at the anode lead to rapid corrosion.[1-3] With steadily increasing energy consumption, the demand for iridium will exceed the available resources in a few decades. As a result, the price of iridium as well as the technologies based on it will continuously increase. An enhancement of PEM electrolysis capacities on a large scale can therefore only be realized in the long term if the application of iridium is significantly reduced.[4] Therefore, our research aims at reducing the iridium content of PEM anodes while maintaining catalytic activity and stability.In this work, two approaches to save iridium were applied. On the one hand the iridium content was reduced by supporting it, on the other hand an additional, readily available metal is incorporated that is protected from corrosion by the presence of iridium and at the same time assists the iridium in catalysis.So, bimetallic included low-loading Ir and different transition metal (Ru, Sn, and Ag) nanoparticles on titanium nitride (TiN) were synthesized by using a chemical reduction method and thermal treatment. Experimentally, a IrSnOx/TiN sample in 0.5 M H2SO4 with an Ir loading of 0.05 mgIr/cm2 achieves a mass activity of over 450 A/gIr at 1.6 V vs RHE and an overpotential of 297 mV at 10 mA/cm2. The investigation includes stability tests at constant current density of 10 mA/cm2 and determination of impedance by electrochemical impedance spectroscopy (EIS).As result, a suitable anode material was successfully achieved, which exhibits a similarly good activity and stability values compared to the IrO2 materials that have been used industrially so far, but with a significantly reduction of iridium to 24% of the usually applied amount.[1] C. Minke, M. Suermann, B. Bensmann, R.H. Rauschenbach, Int. J. Hydrog. Energy, 2021, 46, 23581-23590.[2] F. Scarpelli, N. Godbert, A. Crispini, I. Aiello, Inorganics, 2022, 10, 115.[3] J. Gao, Y. Liu, B. Liu, K.W. Huang, ACS Nano, 2022, 16, 17761-17777.[4] T. Reier, H. N. Nong, D. Teschner, R. Schlögl, P. Strasser, Adv. Energy Mater., 2017, 7, 1601275.

Iridium Single Atoms to Nanoparticles: Nurturing the Local Synergy with Cobalt-Oxide Supported Palladium Nanoparticles for Oxygen Reduction Reaction.

A ternary catalyst comprising Iridium (Ir) single-atoms (SA)s decorated on the Co-oxide supported palladium (Pd)nanoparticles (denoted as CPI-SA) is developed in this work. The CPI-SA with 1wt.% of Ir exhibits unprecedented high mass activity (MA) of 7173 and 770mA mgIr -1, respectively, at 0.85 and 0.90V versus RHE in alkaline ORR (0.1m KOH), outperforming the commercial Johnson Matthey Pt catalyst (J.M.-Pt/C; 20wt.% Pt) by 107-folds. More importantly, the high structural reliability of the Ir single-atoms endows the CPI-SA with outstanding durability, where it shows progressively increasing MA of 13 342 and 1372mA mgIr -1, respectively, at 0.85 and 0.90V versus RHE up to 69 000 cycles (3 months) in the accelerated degradation test (ADT). Evidence from the in situ partial fluorescence yield X-ray absorption spectroscopy (PFY-XAS) and the electrochemical analysis indicate that the Ir single-atoms and adjacent Pd domains synergistically promote the O2 splitting and subsequent desorption of hydroxide ions (OH-), respectively. Whereas the Co-atoms underneath serve as electron injectors to boost the ORR activity of the Ir single-atoms. Besides, a progressive and sharp drop in the ORR performance is observed when Ir-clusters and Ir nanoparticles are decorated on the Co-oxide-supported Pd nanoparticles.

Ir Nanoparticles Supported on Oxygen-Deficient Vanadium Oxides Prepared by a Polyoxovanadate Precursor for Enhanced Electrocatalytic Hydrogen Evolution.

Developing highly active electrocatalysts is crucial for the application of electrocatalytic water splitting. In this study, we prepared vanadium oxide-graphene carbon nanocomposites (VxOy/C) with abundant defects using a carbon- and oxygen-rich hexavanadate derivative Na2[V6O7{(OCH2)3CCH3}4] as a precursor without the addition of an extra carbon source. Subsequently, the VxOy/C was used as a catalyst support to load a small amount of Ir, forming the Ir/VxOy/C nanoelectrocatalyst. This catalyst exhibited low hydrogen evolution overpotentials of only 18.90 and 13.46 mV at a working current density of 10 mA cm-2 in 1.0 M KOH and 0.5 M H2SO4 electrolyte systems, outperforming the commercial Pt/C catalysts. Additionally, the catalyst showed excellent chemical stability and long-term durability. This work provides a new strategy for the design and synthesis of highly active electrocatalysts for water splitting.

Redispersing Ir Nanoparticles via a Carbon-Assisted Pyrolysis Process to Break the Activity-Stability Trade-Off of H2 Sensors.

Oxide semiconductor-supported metal nanoparticles often suffer from a high-temperature gas sensing process, resulting in agglomeration and coalescence, which significantly decrease their surface activity and stability. Here, we develop an in situ pyrolysis strategy to redisperse commercial Ir particles (∼15.6 nm) into monodisperse Ir species (∼5.4 nm) on ZnO supports, exhibiting excellent sintering-resistant properties and H2 sensing. We find that large-size Ir nanoparticles can undergo an unexpected splitting decomposition process and spontaneously migrate along the encapsulated carbon layer surface during high-temperature pyrolysis of ZIF-8. This resultant monodisperse status can be integrally reserved, accompanying further oxidation sintering. The final Irred/ZnO-450-based sensor exhibits outstanding stability, H2 response (10-2000 ppm), fast response/recovery capability (7/9.7 s@100 ppm), and good moisture resistance. In situ Raman and ex situ XPS further experimentally verify that highly dispersive Ir species can promote the electron transfer process during the gas sensing process. Our strategy thus provides important insights into the design of agglomeration-resistant gas sensing materials for highly effective H2 detection.

Ultra-Low-Potential Methanol Oxidation on Single-Ir-Atom Catalyst.

Methanol oxidation plays a central role to implement sustainable energy economy, which is restricted by the sluggish reaction kinetics due to the multi-electron transfer process accompanied by numerous sequential intermediate. In this study, an efficient cascade methanol oxidation reaction is catalyzed by single-Ir-atom catalyst at ultra-low potential (<0.1 V) with the promotion of the thermal and electrochemical integration in a high temperature polymer electrolyte membrane electrolyzer. At the elevated temperature, the electron deficient Ir site with higher methanol affinity could spontaneous catalyze the CH3OH dehydrogenation to CO under the voltage, then the generated CO and H2 was electrochemically oxidized to CO2 and proton. However, the methanol cannot thermally decompose with the voltage absence, which confirm the indispensable of the coupling of thermal and electrochemical integration for the methanol oxidation. By assembling the methanol oxidation reaction with hydrogen evolution reaction with single-Ir-atom catalysts in the anode chamber, a max hydrogen production rate reaches 18 mol gIr -1 h-1, which is much greater than that of Ir nanoparticles and commercial Pt/C. This study also demonstrated the electrochemical methanol oxidation activity of the single atom catalysts, which broadens the renewable energy devices and the catalyst design by an integration concept.

Ultra‐Low‐Potential Methanol Oxidation on Single‐Ir‐Atom Catalyst

AbstractMethanol oxidation plays a central role to implement sustainable energy economy, which is restricted by the sluggish reaction kinetics due to the multi‐electron transfer process accompanied by numerous sequential intermediate. In this study, an efficient cascade methanol oxidation reaction is catalyzed by single‐Ir‐atom catalyst at ultra‐low potential (&lt;0.1 V) with the promotion of the thermal and electrochemical integration in a high temperature polymer electrolyte membrane electrolyzer. At the elevated temperature, the electron deficient Ir site with higher methanol affinity could spontaneous catalyze the CH3OH dehydrogenation to CO under the voltage, then the generated CO and H2 was electrochemically oxidized to CO2 and proton. However, the methanol cannot thermally decompose with the voltage absence, which confirm the indispensable of the coupling of thermal and electrochemical integration for the methanol oxidation. By assembling the methanol oxidation reaction with hydrogen evolution reaction with single‐Ir‐atom catalysts in the anode chamber, a max hydrogen production rate reaches 18 mol gIr−1 h−1, which is much greater than that of Ir nanoparticles and commercial Pt/C. This study also demonstrated the electrochemical methanol oxidation activity of the single atom catalysts, which broadens the renewable energy devices and the catalyst design by an integration concept.

Self-propelled enzyme-controlled IR-mesoporous silica Janus nanomotor for smart delivery

Here, we report the preparation of a novel Janus nanoparticle with opposite Ir and mesoporous silica nanoparticles through a partial surface masking with toposelective modification method. This nanomaterial was employed to construct an enzyme-powered nanomachine with self-propulsion properties for on-command delivery. The cargo-loaded nanoparticle was provided with a pH-sensitive gate and unit control at the mesoporous face by first attaching boronic acid residues and further immobilization of glucose oxidase through reversible boronic acid esters with the carbohydrate residues of the glycoenzyme. Addition of glucose leads to the enzymatic production of H2O2 and gluconic acid, being the first compound catalytically decomposed at the Ir nanoparticle face producing O2 and causing the nanomachine propulsion. Gluconic acid leads to a pH reduction at the nanomachine microenvironment causing the disruption of the gating mechanism with the subsequent cargo release. This work demonstrates that enzyme-mediated self-propulsion improved release efficiency being this nanomotor successfully employed for the smart release of Doxorubicin in HeLa cancer cells.

Selective electrocatalytic oxidation of ammonia to nitrogen by using titanium dioxide nanorod array decorated with ultrasmall Ir nanoparticles and non-noble metal Fe nanoparticles

Electrochemical ammonia oxidation process through active chlorine has been proposed as a potentially effective method for ammonia removal. Currently, most of the anodes require to use high-stable TiO2 loaded with large particles of noble metal Ru or Ir, which have low activity and high cost. Herein, we prepare ultrasmall and uniform metal nanoparticles of Ir on TiO2 to remove ammonia. Moreover, we use non-noble metal Fe to replace noble metals. The ammonia removal efficiency of Fe/TiO2 under 2 VVS Ag / AgCl during 2 h is 100 % and 94 % of ammonia is converted to N2. The Fe/TiO2 anodes not only have higher catalytic activity but also show excellent stability and reusability. Fe/TiO2 anodes still exhibit excellence activity and selectivity after 1 year. As a common metal, Fe will have more application space than iridium in ammonia removal for its low cost and selectively high efficiency.

Symmetric Catalyst Design Employing Ir Nanoparticles on Black WO3- x Nanofiber Support for Boosting Water Electrolysis.

The efficient evolution of gaseous hydrogen and oxygen from water is required to realize sustainable energy conversion systems. To address the sluggish kinetics of the multielectron transfer reaction, bifunctional catalyst materials for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) should be developed. Herein, a tailored combination of atomically minimized iridium catalysts and highly conductive black WO3- x nanofiber supports are developed for the bifunctional electrolyzer system. Atomic Ir catalysts, particularly those that activate the OER, minimize the utilization of precious metals. The oxygen-deficient black WO3- x NF support, which boosts the HER, offers increased electronic conductivity and favorable nucleation sites for Ir loading. The Ir-black WO3- x NFs exhibit increased double-layer capacitance, a significantly reduced onset potential, lower Tafel slope, and stable cyclability for both the OER and HER, compared to large-sized Ir catalysts loaded on white WO3 nanofibers. This study offers a strategy for developing an optimal catalyst material with suitable supports for high-performance and economical water electrolysis systems for achieving carbon-negative targets.

Interfacial Electronic Interactions Between Ultrathin NiFe-MOF Nanosheets and Ir Nanoparticles Heterojunctions Leading to Efficient Overall Water Splitting.

Creating specific noble metal/metal-organic framework (MOF) heterojunction nanostructures represents an effective strategy to promote water electrolysis but remains rather challenging. Herein, a heterojunction electrocatalyst is developed by growing Ir nanoparticles on ultrathin NiFe-MOF nanosheets supported by nickel foam (NF) via a readily accessible solvothermal approach and subsequent redox strategy. Because of the electronic interactions between Ir nanoparticles and NiFe-MOF nanosheets, the optimized Ir@NiFe-MOF/NF catalyst exhibits exceptional bifunctional performance for the hydrogen evolution reaction (HER) (η10 = 15mV, η denotes the overpotential) and oxygen evolution reaction (OER) (η10 = 213mV) in 1.0m KOH solution, superior to commercial and recently reported electrocatalysts. Density functional theory calculations are used to further investigate the electronic interactions between Ir nanoparticles and NiFe-MOF nanosheets, shedding light on the mechanisms behind the enhanced HER and OER performance. This work details a promising approach for the design and development of efficient electrocatalysts for overall water splitting.

Development of an Ir/TiO2 catalytic coating for plasma assisted hydrogenation of CO2 to CH4

The hydrogenation of CO2 to methane over a 20 wt% Ir/TiO2 catalytic coating has been investigated in a tubular dielectric barrier discharge (DBD) reactor. The 1.2 µm Ir/TiO2 coating was deposited onto the inner wall of a quartz tube by a combustion-evaporation method from a mixture containing a Ti precursor and a colloidal suspension of Ir nanoparticles (2 nm). The catalyst was characterised by XRD, SEM, TEM/EDS and CO chemisorption. The Ir(0) state in the as-synthesised film was confirmed by XPS. The CH4 conversion increased by 1.5 times, as compared to an empty tube. A maximum CO2 conversion rate of 2.1 μmol s−1 was achieved at a fuel production efficiency of 3.5%. Surface reactions onto the catalyst surface are responsible for enhancement of reaction rate. The results presented in this work open up new possibilities in plasma-catalysis, whereby efficient reactions can be carried out over small volumes of catalyst.

Size and shapes effect on structural and phonon density of state in Ir nanoparticle and mechanical properties of Ir metal

Density Functional Theory (DFT) calculations were performed to assess the mechanical properties of an Ir metal nanocluster. The properties under investigation encompassed the bulk modulus, Poisson ratio, elastic shear modulus, and binding energy. The stability of the nanocluster was explored across various shapes, including icosahedron, octahedron, and truncated octahedron, with consideration given to different cluster sizes. The DFT results unveiled a general mechanism for amorphization in the Ir nanocluster of size 55, involving rosette-like structural transformations at the fivefold vertex. Additionally, Phonon Density of States (PDOS) was computed for the core, surface, and total atoms of Ir nanoclusters with sizes 38, 55, and 75, as well as for the Ir bulk structure. These calculations were carried out using both Quantum Sutton-Chen potential (QSC) and Gupta potential models through molecular dynamics (MD) methods. The analysis of the phonon density of states revealed that the contributions of two main peaks in low and high frequencies were associated with the surface and core atoms, respectively. Furthermore, the extension of the phonon density of states was performed for larger-sized Ir nanoclusters. Significantly, the QSC potential was utilized to investigate the adsorption of main peaks and their trends for the phonon density of states in the Ir bulk structure. The results obtained from this method were found to be in agreement with experimental data derived from cold neutron and multidetector time-of-flight spectrometer phonon measurements.

Iridium nanoparticles supported on polyaniline nanotubes for peroxidase mimicking towards total antioxidant capacity assay of fruits and vegetables

In this study, a straightforward approach is presented for the first time to anchor Ir nanoparticles on the surface of uniform polyaniline (PANi) nanotubes (NTs), which can be used as an efficient peroxidase (POD)-like catalyst. The morphology and chemical structure of the PANi-Ir nanocomposite are characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffractometer (XRD), Raman and X-ray photoelectron spectroscopy (XPS) measurements. Owing to the strong interaction between Ir nanoparticles and PANi, a remarkable catalytic enhancement is achieved compared to the bare Ir black catalyst and individual PANi NTs, dominating withan electron transfer mechanism. Furthermore, an efficient colorimetric sensor for ascorbic acid (AA) is developed with a low detection limit of 1.0 μM (S/N = 3), and a total antioxidant capacity (TAC) sensing platform is also constructed for the rigorous detection and analysis of fruits and vegetables.

Highly stereoselective hydrogenation of α‑pinene over Ir nanoparticles confined in SiO2 shells

The highly stereoselective hydrogenation of α-pinene was very important and challenging in the utilization of natural products at mild conditions. Here, we reported a core–shell catalyst coated with Ir metal particles by mesoporous silica shell, and revealing the dependence of reducing agents during the preparation process. The prepared nano catalyst exhibited excellent performance in the hydrogenation of chiral substance α-pinene, especially under very mild conditions (40 °C, 1 MPa H2 and 2 h), with a yield of cis-pinane reaching ∼99 %. The characterization methods revealed that the excellent performance was attributed to the strong hydrogenolysis ability of Ir particles. DFT results further indicated that α-pinene can stably adsorb on the edge sites of Ir metal in a cis structure, thereby achieving highly stereoselective hydrogenation. This work utilized heterogeneous catalysis to achieve performance close to that of homogeneous catalysts. The stable core shell structure greatly prolonged the lifespan of the catalyst and overcame the drawbacks of homogeneous catalysts. This work provided more reference cases for chiral hydrogenation.

Defect Engineering Promoted Ultrafine Ir Nanoparticle Growth and Sr Single‐Atom Adsorption on TiO2 Nanowires to Achieve High‐Performance Overall Water Splitting in Acidic Media

AbstractThis work reports the use of the metal‐support interaction strengthening through defect engineering and single atom adsorption to the supports to increase the catalytic activities of metals. Specifically, the plasma treated TiO2 nanowires with the Ir nanoparticle growth and the Sr single atom adsorption (the Ir@Sr‐p‐TiO2 NWs) are synthesized and demonstrated to be efficient catalysts for OER and HER. They only need overpotentials of 250 and 32 mV to drive 10 mA cm−2 for OER and HER, respectively. Their OER and HER activities are much higher than the commercial IrO2 and Pt/C. The high activities of the Ir@Sr‐p‐TiO2 NWs mainly arise from the strengthened metal‐support interactions between the Ir nanoparticles and the p‐TiO2 NWs, achieved by the plasma generated oxygen defects (Vo·) and the Sr adsorption on the p‐TiO2 NWs. Analysis and DFT calculations indicate that the Vo· and Sr adsorption can promote the charge transfer from the p‐TiO2 NWs to the Ir nanoparticles, optimizing the adsorptions of the OER and HER intermediates on the O‐ and H‐covered Ir nanoparticles. Additionally, the strong metal‐support interactions can increase the stabilities of the Ir NPs against the chemical corrosions, increasing the OER and HER durabilities of the Ir@Sr‐p‐TiO2 NWs.

Ultrafine Iridium Nanoparticles Anchored on Co-Based Metal-Organic Framework Nanosheets for Robust Hydrogen Evolution in Alkaline Media.

A highly promising electrocatalyst has been designed and prepared for the hydrogen evolution reaction (HER). This involves incorporating well-dispersed Ir nanoparticles into a cobalt-based metal-organic framework known as Co-BPDC [Co(bpdc)(H2O)2, BPDC: 4,4'-biphenyldicarboxylic acid]. Ir@Co-BPDC demonstrates exceptional HER activity in alkaline media, surpassing both commercial Pt/C and recent noble-metal catalysts. Theoretical results indicate that electron redistribution, induced by interfacial bonds, optimizes the adsorption energy of water and hydrogen, thereby enhancing our understanding of the superior properties of Ir@Co-BPDC for HER.