Catalysis Program 2026

Catalysis in hydrogenases and other metalloenzymes involved in CO2 transformation only requires Earth-abundant metal centers, the reactivity of which is enhanced thanks to the presence of basic sites acting as proton relays [1] at their vicinity. Such active sites have been used as an inspiration to design new synthetic catalysts harnessing PCET processes to enhance catalytic performance for H2 and CO₂ conversion. We will show how detailed molecular electrochemistry studies can help understanding and quantifying the role of the proton relays related to these remarkable behaviors [2]. We will then show how the immobilization of such catalytic platforms onto surfaces allows the preparation of electrode materials operating with the same principles [3-4]. Then we will focus on the assessment of the intrinsic activity of the metal centres and exemplify how multiple populations of catalysts can be identified, with variable contributions to the electrocatalytic process depoending on their micro-environment. Finally, we will report on post-operando characterisation and investigate how the same micrio-environment impact deactivation pathways of such surface-confined molecular catalysts [5]. [1] Haake, M.; Reuillard, B.; Chavarot-Kerlidou, M.; Costentin, C.; Artero, V., Angew. Chem. Int. Ed. 2024, 63, e202413910. [2] Reuillard, B.; Costentin, C.; Artero, V. Angew. Chem. Int. Ed. 2023, 62, e202302779. [3] Katipamula, S.; Wagner, H.; Kuin, S.;Reuillard, B.; Costentin, C.; Artero, V.; https://doi.org/10.26434/chemrxiv.10002033/v1 [4] Haake, M.; Aldakov, D.; Pérard, J.; Veronesi, G.; Aguilar Tapia, A.; Reuillard, B.; Artero, V.; J. Am. Chem. Soc. 2024, 146, 15345-15355. [5] Haake, M.; Caumes, C.; Saint-Pierre, C.; Gasparutto, D.; Veronesi, G.; Aguilar Tapia, A.; Artero, V.; Reuillard, B.; J. Am. Chem. Soc. 2026, accepted; https://chemrxiv.org/doi/full/10.26434/chemrxiv-2025-0w2l9.

The influence of porosity on the nanostructure and physicochemical properties of graphitic carbon nitride (g-C3N4) remains insufficiently understood from both experimental and theoretical perspectives. In this work, three g-C3N4 materials with distinct morphologies, layered, rod-like, and curved spherical structures, were systematically studied.[1] These materials exhibit pronounced differences in porosity, surface hydrophilicity, optical bandgap, charge transport behavior, and photocatalytic performance for oxygen reduction to hydrogen peroxide (H2O2). Under 410 nm irradiation, the most porous spherical sample achieves an H2O2 production rate of 2.7 mmol·g⁻¹·L⁻¹, which is approximately an order of magnitude higher than that of bulk g-C3N4. To interpret these observations, three theoretical models were employed to decouple the roles of curvature effects, quantum confinement, and their combined influence. The results indicate that curvature induces a bandgap widening in g-C3N4, however, the formation of intrinsic micro- and mesoporosity associated with curved or distorted surfaces is unlikely due to strong interlayer stacking. Instead, the observed mesoporosity is mainly attributed to the assembly of nanoscale crystallites. Transient absorption spectroscopy further reveals that morphology-induced porosity and increased surface area stabilize long-lived electron populations and promote charge separation, thereby enhancing photocatalytic H2O2 production. Overall, this study provides new insights into the relationship between porosity, nanostructure, and photocatalytic function in g-C3N4, highlighting the importance of nanostructure engineering for optimizing performance. [1] L. Ni et al., ChemRxiv, 2025, DOI: 10.26434/chemrxiv-2025-8x7sd.

Density functional theory (DFT) calculations are now routinely used to understand the functioning of heterogeneous catalysts. However, there is still the formidable challenge to identify and construct valid active site motifs of working catalysts at the atomic scale, while also keeping the methodology computationally feasible. Herein, we report a DFT-based Monte Carlo method that can simulate the atomic-scale structure of oxide supported metal particles of sizes up to 10 nm (see Figure 1)Sk.[1] This method revealed new sites for CO splitting on supported Co particles,[2] and we will show here how Pt particles change their surface structure with particle size and what that means for the key selectivity determining steps of ammonia oxidation, namely N-N recombination as well reaction steps towards NO, N2O and NO2 formation. Further, we will also shed light on Pt single atoms supported on the CeO2(111) facet that show an unexpected stability within subsurface interstitial sites as evidenced by IR spectroscopy and DFT calculations.[3] Figure 1: Performance Structural models of Co nanoparticles obtained with a DFT-based Monte Carlo algorithm. The number of Co atoms composing the NPs are given in parentheses. Data from [1]. [1] E. Sireci, T. D. Grüger, P. N. Plessow, D. I. Sharapa, F. Studt, J. Phys. Chem. C, 2025, 129, 13232, DOI: 10.1021/acs.jpcc.5c02777 [2] E. Sireci, D. I. Sharapa, F. Studt, J. Phys. Chem. C, 2025, 129, 21634, DOI: 10.1021/acs.jpcc.5c07278. [3] S. Chen, Z. Yu, J. Wang, J. Jelic, W. Li, F. Studt, Y. Wang, C. Wöll, Angew. Chem. Int. Ed. 2026, e22372.

Photo-induced electron transfer (PET) processes are the cornerstone of natural photosynthetic processes. In this contribution, we present our hierarchical quantum chemical approach to unravel the thermodynamics and kinetics of competitive PET processes associated with catalytic turn-over, charge-recombination and degradation in transition metal-based supramolecular photocatalysts. Within the Marcus picture – a two-state model – both intramolecular and intermolecular PET[1,2] processes are investigated along efficient internal reaction coordinates and ab initio molecular dynamics, respectively. However, such two-state models are insufficient to account for the plethora of electronic excited states involved in photoactive dyad and triad architectures. Therefore, a concept beyond Marcus theory is utilized to cover incomplete population transfer and super-exchange phenomena between an arbitrary number of (excited) states via dissipative quantum dynamics.[3] Implementation of diabatization schemes (e.g. Edmiston-Ruedenberg) allowed us to extend our molecular perspective to electrode materials, i.e. to model electron transfer processes of molecular entities embedded in redox-active polymers.[4] Figure 1: Competitive PET channels in transition metal-based photocatalysts and theoretical extension to model these in a n-state model beyond Marcus theory by means of dissipative quantum dynamics.[3] [1] G. E. Shillito et al., ChemCatChem, 2023, 15, e202201489, . [2] G. Yang et al., Chem. Sci., 2025,16, 18113. [3] G. Yang et al., Chem. – Eur. J., 2025, 31, e202404671. [4] C. Zens et al., ChemSusChem, 2026, 19, e202502645.

Mass-selected metal clusters supported on oxide surfaces serve as powerful model catalysts for probing fundamental aspects of heterogeneous catalysis. In our work, we investigate Pt₂₀₀ clusters supported on pulsed laser-deposited CeO₂, prepared via Cluster Ion Beam Deposition (CIBD)1 directly onto a MEMS reactor device. This setup facilitates operando Scanning Transmission Electron Microscopy (STEM), allowing real-time imaging under controlled heating and gas flow. During CO oxidation, the CO2 generation and the level of conversion at different temperatures have been monitored using a high sensitivity residual gas analyzer (RGA). In addition, identical location STEM experiments are also conducted to understand the effect of e- beam on the cluster dynamics and to assess its effect on the catalytic process. Beyond operando catalytic conditions, the catalyst is examined in oxidative and reductive environments to visualize Pt-CeO₂ interactions in fresh, spent and rejuvenated states. Under oxidative treatment (≥600 °C), Pt₂₀₀ clusters disperse into single atomic sites, forming PtOx and Ptn⁺-O-Ce species2. Upon reduction with H₂ at 800 °C, cluster reformation is observed, revealing reversible structural dynamics and Strong Metal-Support Interactions (SMSI). The Ce oxidation states at both oxidized and reduced states have been analyzed using electron energy loss spectroscopy (EELS). The observations are compared to an analogous model catalyst tested independently in a flow reactor to validate the operando STEM findings. This integrated approach bridges atomic-scale imaging with catalytic performance, offering comprehensive insights into structure-activity relationships in cluster-based model catalysts. [1] A. Fischer et al., Rev Sci Instrum. 2015, 86, 023304, DOI: 10.1063/1.4908166. [2] F. Maurer et al., Nat. Catal. 2020, 3, 824–833, DOI: 10.1038/s41929-020-00508- 7.

The development of efficient strategies for the synthesis and diversification of complex molecules remains a central challenge in organic chemistry. The Ngai laboratory seeks to address this challenge by developing new approaches to build and modify molecules, with the long-term vision of turning light into medicine. Our research focuses on the use of visible-light-driven excited-state catalysis to transiently reprogram molecular reactivity and enable transformations that are difficult to achieve under conventional ground-state conditions. By combining photochemistry, radical reactivity, and transition-metal catalysis, we aim to establish general platforms for selective bond construction and late-stage functionalization of structurally complex molecules. These efforts include the development of new catalytic strategies for site-selective modification, carbon–heteroatom bond formation, and the introduction of functional groups relevant to medicinal, agrochemical, and materials chemistry. This seminar will highlight recent advances from our laboratory illustrating how excited-state catalysis can enable new strategies for molecular functionalization and provide streamlined access to bioactive molecular architectures. [1] Khosravi, A.; Zhang, Y.; Zhao, G.; Radefeld, K. J.; Sharma, S.; Pannilawithana, N. A.; Zhang, Y.; Liu, P.*; Ngai, M.-Y.*, J. Am. Chem. Soc. 2025, 147, 27197, DOI: 10.1021/jacs.5c08537. [2] Zhao, G.; Mukherjee, U.; Yao, W.; Ngai, M.-Y.*, Acc. Chem. Res. 2025, 58, 1815, DOI: 10.1021/acs.accounts.5c00205. [3] Zhao, G.; Lim S.; Musaev, D. G.; Ngai, M.-Y.*, J. Am. Chem. Soc. 2023, 145, 8275, DOI: 10.1021/jacs.2c11867. [4] Zhao, G.#; Yao, W.#; Mauro, J. N.; Ngai, M.-Y.* J. Am. Chem. Soc. 2021, 143, 1728, DOI: 10.1021/jacs.0c11209.

The second time-resolution provided by Quick-EXAFS beamlines on 3rd generation synchrotron radiation facilities makes the technique powerful for unraveling reaction pathways of catalysts in working conditions. Recently, the Full Field (FF) hyperspectral Quick-XAS imaging, offering micrometer-scale spatial resolution in addition to the time resolution together with the element-specific information provided by X-ray Absorption Spectroscopy (XAS), has been implemented at the ROCK-SOLEIL beamline [1]. FF XAS imaging is based on the recording of the visible light emitted by a scintillator imaging the sample absorption by a pixelated CMOS camera (ORCA Flash 4.0 V3, Hamamatsu) equipped with a X4 magnification objective (pixel size and Field of View (FoV) 1.625 μm and 3.3 mm, respectively. Images at different energies of the XAS spectrum are collected during the monochromator energy scan yielding to one complete hyperspectral cube every 2 to 11 s depending on the oscillation frequency. Spectra normalization, energy alignment, spatial pixel binning or cube binning are based on home-made Jupyter notebooks. Speciation in the cube is obtained by Multivariate Curve Resolution with Alternating Least Square (MCR-ALS) analysis. In this lecture, we will illustrate the capability of the full-field hyperspectral spatio- temporal technique implemented at ROCK for monitoring the thermal activation of catalysts [1] and their regeneration after use [2]. Figure 1: FF Quick-EXAFS hyperspectral imaging of the monitoring of the oxidative regeneration of a NiCu-based spent catalyst used for Ethanol Steam Reforming [2] [1] V. Briois et al., J. Synch. Rad., 2024, 31, 1084, 10.1107/S1600577524006581 [2] V. Briois et al., ChemCatChem, 2024, 16, e202400352, 10.1002/cctc.202400352

Meeting increasingly stringent emission standards requires strategies that maximize catalyst efficiency. Against this background, forced dynamic operation (FDO) offers a means to overcome kinetic and thermodynamic limitations in emission control. This work investigates FDO in three applications: three‑way catalysis, methane oxidation, and selective ammonia oxidation. For this, Pd‑based catalysts were synthesized and evaluated through kinetic studies and ex situ/in situ characterization as powders and washcoated substrates. In three‑way catalysis, high‑frequency lean–rich cycling mitigates CO and O2 poisoning, enabling frequency‑dependent optimization of activity and selectivity. For methane oxidation, short rich pulses during lean operation improve light‑off performance and long‑term stability, with spatiotemporal studies identifying palladium redox gradients and hydroxyl removal as key to sustained CH4 activation. In NH3 oxidation, FDO promotes coexistence of metallic Pd and PdO, enhancing activity and selectivity beyond state‑of‑the‑art catalysts. These results demonstrate that rational dynamic operation enables low‑temperature abatement while reducing catalyst volume, cost, and reliance on scarce materials. Figure 1: Performance improvement driven by FDO (dashed lines) compared to time-invariant constant gas streams (solid lines) for a) selective ammonia oxidation in excess oxygen, b) lean methane oxidation, and c) three-way catalysis. Data from [1-3]. [1] D. Hodonj, B. Thiele, O. Deutschmann, P. Lott, Chem. Eng. J., 2024, 499, 155852, DOI: 10.1016/j.cej.2024.155852. [2] K. Keller, D. Hodonj, L. Zeh, L. Caulfield, E. Sauter, C. Wöll, O. Deutschmann, P. Lott, Catal. Sci. Technol., 2024, 14, 4142-4153, DOI: 10.1039/D4CY00625A. [3] T. Häber, C. Cárdenas, O. Deutschmann, P. Lott, 2026, submitted.

In synthetic settings, the prevention of catalyst deactivation from chemical changes to its molecular structure during active operation is the primary concern and remains elusive.[1] Inspired by membrane and protein integration of the natural photosynthetic apparatus of green plants ensuring structural integrity of key components, we report a photocatalytically active rotaxane mimicking photosystem I. In our Ru-Rh dyad system the two metal centers are connected by sensitive alkyne-units. By strategically burying the bridging ligand in a macrocycle cavity, i.e. in cucurbit[7]uril, the heterodinuclear rotaxane photocatalyst preserves both, structural integrity and activity of its components. Superior, long-term photocatalytic activity under enzyme-like H-bond-driven substrate preorganization at the catalytic center. These results underscore the pivotal function of rationally engineered interplay between supramolecular assemblies in catalysis and open new catalytic paradigms for advanced and sustainable supramolecular methodologies, with direct applications in artificial photosynthesis and light-driven water splitting.[2] Figure 1: (a) Simplified representation of PS I, showing the special pair used for light absorption (cyan), followed by the molecular wire (Fe4S4 clusters & ferredoxin) connecting the special pair with the ferredoxin-NADP+ reductase (FNR) serving as catalyst (CAT, purple). The molecular wire is shielded in a protective protein shell (orange helix). The FNR forms a precomplex with NADP+ in its enzymatic pocket before conversion to NADPH takes place. (b) Chemical depiction of the herein presented PS I-mimicking rotaxane, showing the NAD+ precomplex formation in its artificial binding pocket. Catalytic conversion of NAD+ to NADH can be obtained either by photocatalysis or thermal catalysis. (c) Schematic depiction of the investigated rotaxane used in this study. [1] Zedler, L., et al. Outpacing conventional nicotinamide hydrogenation catalysis by a strongly communicating heterodinuclear photocatalyst. Nat Commun 13, 2538 (2022). [2] Müßler, M. et al. A Photocatalytically Active Rotaxane Mimicking Photosystem I. ChemRxiv (2025). doi:10.26434/chemrxiv-2025-1nsr5.

Structured emission control catalysts are typically implemented as washcoated monolithic honeycombs, where catalytic performance is governed not only by intrinsic reaction kinetics but also by catalyst architecture and spatially heterogeneous aging phenomena[1]. In this work, complementary hard X-ray imaging techniques were applied to investigate structured catalysts across multiple length scales. Multiscale X-ray tomography was used to characterize the architecture of washcoated Pd/Al2O3 monolith catalysts, enabling quantitative three-dimensional analysis of washcoat morphology, channel accessibility, and structural changes during catalyst aging. Complementary X-ray absorption spectroscopy was employed to investigate chemical transformations in washcoated Cu-SSZ-13 monolith catalysts under reaction conditions[2]. This enabled spatially resolved mapping of Cu speciation within the washcoat, providing insight into catalyst deactivation processes and the spatial distribution of active species during operation. Together, these studies demonstrate how multimodal and multiscale X-ray imaging provides a powerful framework for linking catalyst structure, chemical state, and performance in technically relevant emission control catalysts. Figure 1: Structural and chemical investigation of washcoated monolith. [1] J. Becher et al., JPCC, 2019, 123, 41, 10.1021/acs.jpcc.9b06541. [2] J. Becher et al., Nat. Catal., 2021, 4, 46-53, 10.1038/s41929-020-00552-3.

Ionic carbon nitrides based on poly(heptazine imides) (PHI) are a widely studied class of polymeric materials with applications in photo(electro)catalysis and energy storage. This contribution will highlight our recent achievements in developing PHI- based photocatalyst for light-driven H₂O₂ production and PHI-based photoanodes exhibiting interesting properties, including photodoping and very negative photocurrent onset potentials [1–4]. The intriguing properties of PHIs, with particular emphasis on our recent photoelectrochemical, spectroscopic, and theoretical insights into their peculiar photophysics and photo(electro)catalysis, will be discussed [5–8]. [1] I. Krivtsov, D. Mitoraj, C. Adler, M. Ilkaeva, M. Sardo, L. Mafra, C. Neumann, A. Turchanin, C. Li, B. Dietzek, R. Leiter, J. Biskupek, U. Kaiser, C. Im, B. Kirchhoff, T. Jacob, R. Beranek, Angew. Chem. Int. Ed. 2020, 59, 487. [2] I. Krivtsov, A. Vazirani, D. Mitoraj, M. M. Elnagar, C. Neumann, A. Turchanin, Y. Patiño, S. Ordóñez, R. Leiter, M. Lindén, U. Kaiser, R. Beranek J. Mater. Chem. A 2023, 11, 2314. [3] C. Adler, I. Krivtsov, D. Mitoraj, L. dos Santos-Gómez, S. García-Granda, C. Neumann, J. Kund, C. Kranz, B. Mizaikoff, A. Turchanin, R. Beranek, ChemSusChem 2021, 14, 2170. [4] C. Adler, S. Selim, I. Krivtsov, C. Li, D. Mitoraj, B. Dietzek, J. R. Durrant, R. Beranek, Adv. Funct. Mater. 2021, 31, 2105369. [5] C. Im, B. Kirchhoff, I. Krivtsov, D. Mitoraj, R. Beranek, T. Jacob, Chem. Mater. 2023, 35, 1547. [6] C. Im, B. Kirchhoff, D. Mitoraj, I. Krivtsov, A. Farkas, R. Beranek, T. Jacob, J. Mater. Chem. C 2025, 13, 8682. [7] C. Im, R. Beranek, T. Jacob, Adv. Energy Mater. 2025, 15, 2405549. [8 ] A. Konar, J. Liessem, Ch. Im, M. M. Elnagar, D. Mitoraj, P. Saini, I. Krivtsov, S. J. Finkelmeyer, J. Griebel, M. Presselt, T. Jacob, R. Beranek, B. Dietzek-Ivanšić, Adv. Sci. 2025, 12, e09312.

Machine learning (ML) has transformed ground-state molecular predictions using large-scale foundational models such as variants of the message-passing atomic cluster expansion (MACE) model, but excited states and catalysis demand innovative solutions to data scarcity. For theoretical photochemistry, we demonstrate how our excited-state extension, X-MACE [1,2], achieves chemical transferability across electronic states with little additional excited-state data, enabling accurate photochemical property predictions for molecules and extended systems. This method will be showcased on green fluorescent protein chromophores to screen dynamics and revealing rational design principles. For experimental approaches, we present two algorithms: (1) active curation balancing experiment count, model accuracy, and iterative labeling; (2) subset selection from existing datasets. Both enable robust ML models from sparse data that can be used, for instance, to predict yields or optimize reaction conditions. [1] Rhyan Barrett, Sophia Wesely, and Julia Westermayr. "Transferable excited-state dynamics enable screening of fluorescent protein chromophores" arXiv preprint 2026 arXiv:2604.12699. [2] Rhyan Barrett, Johannes CB Dietschreit, and Julia Westermayr. "Incorporating long-range interactions via the multipole expansion into ground and excited-state molecular simulations" npj Computational Materials 2026 12(135), DOI: 10.1038/s41524-026-02048-3

In the context of sustainable energy scenarios and the quest for carbon-free energy vectors, NH3 is considered an attractive fuel since it is produced globally on a huge scale from N2, has a high energy density and is readily transported. NH3 stores energy in its N−H bonds, but the ammonia oxidation reaction (AOR; NH3 to N2) is challenging as it requires orchestration of multiple H+ and e− transfers as well as the N−N coupling, which can occur from several types of M−NHx intermediates and may follow different mechanisms (Figure 1). Homogenous AOR catalysts have evolved in recent years and provide mechanistic insight, enabling targeted ligand design for improving catalytic performance and elucidating decomposition pathways.1,2 Here we present detailed studies on mono- and dinuclear Ru-based AOR electrocatalysts (1, 2) that mediate N−N bond formation at an early amido stage of the PCET map to avoid higher metal oxidation states and to operate at rather low overpotentials.3,4 Figure 1: Mechanistic pathways for the metal-mediated ammonia oxidation reaction (AOR) [1] P.L. Dunn et al., J. Am. Chem. Soc., 2020, 142, 17845, DOI: 10.1021/jacs.0c08269. [2] J. Li et al., Sci. China Chem., 2024, 67, 3976, DOI: 10.1007/s11426-024-2137-5 [3] M. Seiß et al., ACS Catal., 2025, 15, 20531, DOI: 10.1021/acscatal.5c05769 [4] M. Seiß et al., submitted for publication.

Lewis acids have been evolved as catalysts, which can change the course of organic reactions dramatically. The application of Lewis acids in light-driven reactions of carbonyl compounds is a powerful instrument to influence the outcome of a photoreaction. Employing Lewis acids, we were able to control the enantioselectivities of an ortho photocycloaddition reaction as well as a visible light- triggered cycloaddition / rearrangement cascade of aromatic aldehydes. Furthermore, a fundamental change of the photochemical reactivity pattern of naphthaldehydes with olefins was examined in presence of achiral Lewis acids. Chiral Lewis acids were also successfully applied in an intramolecular ortho photocycloaddition reaction of 2‐acetonaphthones. Scheme 1: A: Modulation of Lewis acid–substrate complex. B: Formal [3+2] photocycloaddition. In a novel formal [3+2] photocycloaddition reaction of benzaldehyde derivatives, Lewis acids are successfully added to increase the yield by using only catalytic amounts (10 mol%). The robustness of this method was proven by the application of the optimized reaction condition to up to 30 different substrates, possessing electron- donating as well as electron-deficient substituents. Mechanistic studies and successful follow-up transformation of the tricyclic aromatic photoproducts in an arene hydrogenation broadens the horizon of the project.

Electron transfer and proton-coupled electron transfer are ubiquitous in chemistry, for instance in catalysis, along enzymatic charge transport chains, or as intramolecular events in some mixed-valent compounds. In the Marcus–Hush model, electron transfer (ET) results in a change in diabatic potential energy surfaces, separated along an ET nuclear coordinate. This coordinate accounts for all nuclear motions that promote electron transfer. It is usually assumed to be dominated by a collective asymmetric vibrational motion of the redox sites involved in the ET, but it is rarely quantitatively specified. We have recently proposed an ab initio approach for quantifying the ET coordinate in mixed-valence compounds.[1] Using sampling methods at finite temperature combined with density functional theory calculations, we find that the electron transfer can be followed using the energy separation between potential energy surfaces and the extent of electron localization. The precise nuclear motion that leads to electron transfer is then obtained as a linear combination of normal modes. We demonstrate this approach for a series of dinitroradical anions[1] and the famous Creutz–Taube ion.[2, 3] We will then discuss how our approach for quantifying ET coordinates can be translated to proton-coupled electron transfer reactivity.[4] Using examples that are representative of concerted proton-electron transfer and hydrogen atom transfer –two distinct regimes within proton-coupled electron transfer– we discuss how the nature of the process is reflected in the ab initio calculations. [1] A. Šrut, B. J. Lear, V. Krewald, Chem. Sci. 2023, 14, 9213-9225. [2] C. Creutz, H. Taube, J. Am. Chem. Soc. 1969, 91, 3988. [3] A. Šrut, B. J. Lear, V. Krewald, Angew. Chem. 2024, 63, e202404727. [4] A. Šrut, M. Diefenbach, M. L. Kronenberger, B. J. Lear, V. Krewald, preprint available on ChemRxiv. 2025, DOI: 10.26434/chemrxiv-2025-36d35.