Zeolite-encapsulated metal (metal@zeolite) catalysts combine the advantages of nonporous materials and metal/ metal oxide nanoparticles, which exhibit excellent sintering resistance and metal utilization. Among them, mordenite (MOR) showed outstanding selectivity in the carbonylation of dimethyl ether but suffered from limited activity. Herein, mordenite zeolite-encapsulated metal (Co, Ni, Cu, and Zn) catalysts were successfully prepared by the one-step method. Comprehensive characterization results confirmed the crystallinity of MOR is not affected by in situ encapsulation, and the metal particles are uniformly and highly dispersed in the zeolite matrix. The activity test results show that Cu@HMOR exhibits extraordinary activity for DME carbonylation with the conversion of DME (74.6 %) and the selectivity of MA (95.6 %) due to the large number of Br & Oslash;nsted acid sites. The synthesis method provides an innovative and facile idea for constructing and developing zeoliteencapsulated metal nanoparticle catalysts.

Recent studies have revealed that the slow kinetics of active free water molecule replenishment on the surface of catalyst can be the potential cause responsible for the sluggish reaction kinetics of oxygen evolution reaction (OER) under acidic electrolyte. However, engineering the dynamic interfacial water structure to form the free water enriched microenvironment has rarely been implemented due to the relatively inherent inert catalyst surface. Herein, we demonstrate that surface modification of ruthenium dioxide (RuO2) with PO43-anions (RuP0.4Ox) can effectively regulate the free water enriched microenvironment and significantly enhance the acidic OER performance. Experimental results including operando attenuated total reflectance surface-enhanced infrared absorption spectroscopy reveal that the introduction of PO43-species can manipulate the interfacial water structure, resulting in a free-H2O-enriched interfacial environment, which is conducive to the continuous supply of reactants. Moreover, theoretical studies indicate that the surface modified PO43-could facilitate proton transfer to the oxygen sites of the PO43-group, enabling a PO43--assisted adsorption evolution mechanism with enhanced reaction kinetics. Consequently, the obtained RuP0.4Ox catalyst, featuring a Ru-O-P local environment and modified by surface PO43-anions, displays a low overpotential of 200 mV at 10 mA cm-2 and operates stably for 500 h during the acidic OER process. (c) 2026, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Understanding the effect of noncovalent interactions of intermediates at the polarized catalyst-electrolyte interface is key to improving the kinetics of electrocatalytic reactions. Herein, we employ cobalt oxyhydroxide (CoOOH) as a model catalyst, select carboxylate-based additives to strategically modulate the interfacial electronic double layer (EDL), and investigate the effect of carboxylate anions on the oxygen evolution reaction (OER) kinetics under alkaline media. We demonstrate that the hydrogen bonds formed between oxygen atoms within -COO- fragments of carboxylate anions and interfacial H2O molecules can disrupt the arrangement of the hydration shell around K+, leading to fast migration of OH- to the CoOOH surface. Experimental results, including rotating ring-disk electrode (RRDE) measurements, in situ X-ray absorption spectroscopy (XAS), in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), and ab initio molecular dynamics (AIMD) theory simulations, reveal that the negative electrostatic potential on the oxygen atom in the -COO- fragments can partially neutralize the localized electric field generated by hydrated K+ ions in the electrolyte, which sufficiently destabilizes the adsorbed oxygenated intermediates and accelerates the deprotonation process, thereby leading to promoted charge accumulation and accelerated alkaline OER kinetics.

Understanding and engineering interfacial water structure at electrochemical interfaces is critical for optimizing the hydrogen evolution reaction (HER) in alkaline media. Herein, we propose a supramolecular strategy to engineer the electrode/electrolyte interface by modifying Pt, Ru, and Ir nanoparticles with cucurbit[6]uril (CB6/ M, M = Pt, Ru, Ir), a macrocyclic host that selectively binds cations with its carbonyl portals through ion-dipole interactions. Through a combination of in situ surface-enhanced infrared absorption spectroscopy, zeta potential and density functional theory (DFT) calculations, we demonstrate that CB6-functionalized catalysts (CB6/M) significantly enrich interfacial cation concentrations, thereby restructuring the hydrogen-bond network of interfacial water, which promotes the formation of flexible water configurations, like 2HB-H2O and K+ - (H2O)x at the electrode/electrolyte interface. Furthermore, operando local pH measurements and DFT calculation reveal that the CB6-induced cation-rich environment enhances OH- transfer across the electrical double layer. As a result, CB6/Pt, CB6/Ru, and CB6/Ir exhibit superior HER activities in alkaline media, outperforming their unmodified counterparts. This work establishes a general supramolecular approach to tailor interfacial water structure for improved electrocatalysis, offering broad applicability to other energy conversion systems.

The development of highly efficient and stable Co3O4-based electrocatalysts as promising alternatives to IrO2 for the acidic oxygen evolution reaction (OER) is needed to support broader commercialisation of a proton exchange membrane water electrolyzer (PEMWE). Unfortunately, the activity of Co3O4 is severely hindered by the linear scaling relationship through the favorable adsorbate evolution mechanism (AEM). Although considerable efforts have been devoted to promoting the oxygen pathway mechanism (OPM) to bypass the AEM pathway through tailoring the inherent structures of active sites on Co3O4, limited attention has been paid to the role of interfacial water molecules at the catalyst-electrolyte interface. Here, we demonstrate that the acidic OER pathway of Co3O4 can be rationally regulated through partial substitution of octahedral Co atoms in Co3O4 with Sb. We find that the asymmetric Sb-O-Co motif could induce interfacial H2O reorientation into H-down configuration, thus suppressing the nucleophilic attack of H2O molecules on the Co 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 O* intermediate, which is the key for triggering the reaction pathway from the AEM to OPM. Consequently, the obtained Sb0.3Co2.7O4 catalyst exhibits remarkable OER activity and long-term durability, achieving 2 A cm-2 at 2.11 V and stable operation for over 800 hours at 2.0 A cm-2 in a PEMWE device.

Hydrogen binding energy (HBE) is a key thermodynamic descriptor for the hydrogen oxidation reaction (HOR), yet its influence on the interfacial water structure in the electric double layer (EDL) and reaction kinetics, particularly as modulated by adsorbed hydrogen (H-ad) coverage, remains poorly understood. Here, we employ a WO3-supported Ir nanoparticle catalyst (WO3-Ir) to elucidate the impact of H-ad coverage on the EDL structure and HOR kinetics in alkaline media. By integrating electrochemical measurements, in situ surface-enhanced infrared absorption spectroscopy, and theoretical calculations, we demonstrate that strong electronic interaction with WO3 downshifts the Ir d-band center, thereby weakening the HBE and H-ad coverage compared with pure Ir. This lower H-ad coverage alleviates repulsive H-ad-H2O interactions, facilitating hydrogen desorption and proton transfer. Simultaneously, the reduced H-ad-induced surface hydrophobicity enhances water-electrode interactions and narrows the interfacial gap, thereby enriching asymmetric and weakly hydrogen-bonded water at the interface and forming a more connected interfacial water network that facilitates proton-coupled electron transfer across the EDL and accelerates alkaline HOR kinetics. These findings highlight the critical role of H-ad coverage in modulating the interfacial water structure and in governing HOR kinetics in alkaline media.

The rational design of high-performance electrocatalysts for alkaline hydrogen oxidation reaction (HOR) is significant to the widespread commercialization of alkaline exchange membrane fuel cells. However, precise regulation of proton adsorption states and interfacial transfer kinetics at the catalytic interface remains a significant challenge in advancing HOR under alkaline conditions. Herein, we demonstrate that construction of phosphorus-doped carbon-coated nickel (Ni) catalyst (Ni@PC) featuring the bridging oxygen structures (Ni–O–C/P) enables rapid desorption of adsorbed hydrogen species and dynamic reconstruction of interfacial hydrogen–bond network. Density functional theory calculations reveal that the Ni–O–P configuration induces a downward shift in the d-band center of Ni, thereby weakening hydrogen binding energy (HBE). Furthermore, the bridging oxygen atoms facilitate the formation of hydrogen bonds with interfacial water molecules, optimizing the proton transfer pathway. In-situ surface-enhanced infrared absorption spectroscopy confirms that the Ni–O–P structure effectively converts weakly hydrogen-bonded water into strongly hydrogen-bonded water, enhancing the connectivity of hydrogen-bond network and facilitating efficient proton transfer. This work successfully achieves optimization of proton dynamics during the alkaline HOR progress, while also providing a strategic framework for the rational design of advanced carbon-coated electrocatalysts.

Exploring the alkaline hydrogen oxidation reaction (HOR) catalysts with outstanding activity and the CO tolerance ability is essential for the practical promotion of anion exchange membrane fuel cell (AEMFC). Herein, we introduce oxophilic Sn element into Pt3Ga intermetallic compound to obtain the Sn-doped Pt3Ga (Sn-Pt3Ga). Combined CO stripping results and theoretical calculations, the OH adsorption ability of Sn-Pt3Ga is enhanced compared to Pt3Ga and Pt. As a result, the Sn-Pt3Ga presents elevated intrinsic activity and mass activity of 0.690 mA cm(-2) and 1.52 mA & micro;g(-1), which are 3 times higher than those of commercial Pt. In addition, the d band center of Pt in Sn-Pt3Ga shifts to the lower energy, contributing to the decreased adsorption of CO on the surface. Thus, the CO anti-poisoning of Sn-Pt3Ga is improved with only 6.02% decay of the HOR activity after the CO poisoning, while Pt shows 44.7% decay.

Hydrogen oxidation reaction (HOR) exhibits a pH dependent behavior that the kinetics in acidic media are two to three orders of magnitude compared to that in alkaline media. Herein, to address the kinetic limitation on alkaline HOR, a series of Ru-based catalysts are constructed via introducing rare-earth oxides. The constructed Ru-SmOx/C catalyst exhibits reversed pH-dependent HOR behavior, achieving superior performance in alkaline media compared to acidic media. Notably, the introduction of strongly oxophilic SmOx can substantially increase the active sites for adsorbing OH species, alleviating the competitive behaviors and ensuring the synergistic interaction among diverse intermediates. Furthermore, the abundant strongly bonded surface OH species interact intensely with K+, releasing more free water molecules into the gap region and restructuring interfacial hydrogen-bond network, as confirmed by in situ surface-enhanced infrared absorption spectroscopy. Consequently, these synergistic effects promote proton-coupled electron transfer (PCET) at the electrode-electrolyte interface, thereby markedly accelerating the alkaline HOR kinetics and even resulting in the reversed pH effect. This work elucidates the pivotal roles of oxophilic promoters in synergistically modulating intermediate behavior and interfacial microenvironment, especially, in restructuring the hydrogen-bond network, which provides strategies for designing high-performance Ru-based HOR electrocatalysts and fundamental insights into pH-dependent electrocatalytic reactions.

The rational design of high-performance electrocatalysts for alkaline hydrogen oxidation reaction (HOR) is significant to the widespread commercialization of alkaline exchange membrane fuel cells. However, precise regulation of proton adsorption states and interfacial transfer kinetics at the catalytic interface remains a significant challenge in advancing HOR under alkaline conditions. Herein, we demonstrate that construction of phosphorus-doped carbon-coated nickel (Ni) catalyst (Ni@PC) featuring the bridging oxygen structures (Ni-O-C/P) enables rapid desorption of adsorbed hydrogen species and dynamic reconstruction of interfacial hydrogen-bond network. Density functional theory calculations reveal that the Ni-O-P configuration induces a downward shift in the d-band center of Ni, thereby weakening hydrogen binding energy (HBE). Furthermore, the bridging oxygen atoms facilitate the formation of hydrogen bonds with interfacial water molecules, optimizing the proton transfer pathway. In-situ surface-enhanced infrared absorption spectroscopy confirms that the Ni-O-P structure effectively converts weakly hydrogen-bonded water into strongly hydrogen-bonded water, enhancing the connectivity of hydrogen-bond network and facilitating efficient proton transfer. This work successfully achieves optimization of proton dynamics during the alkaline HOR progress, while also providing a strategic framework for the rational design of advanced carbon-coated electrocatalysts. (c) 2026, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

ABSTRACT Exploring the alkaline hydrogen oxidation reaction (HOR) catalysts with outstanding activity and the CO tolerance ability is essential for the practical promotion of anion exchange membrane fuel cell (AEMFC). Herein, we introduce oxophilic Sn element into Pt 3 Ga intermetallic compound to obtain the Sn‐doped Pt 3 Ga (Sn‐Pt 3 Ga). Combined CO stripping results and theoretical calculations, the OH adsorption ability of Sn‐Pt 3 Ga is enhanced compared to Pt 3 Ga and Pt. As a result, the Sn‐Pt 3 Ga presents elevated intrinsic activity and mass activity of 0.690 mA cm −2 and 1.52 mA µg −1 , which are 3 times higher than those of commercial Pt. In addition, the d band center of Pt in Sn‐Pt 3 Ga shifts to the lower energy, contributing to the decreased adsorption of CO on the surface. Thus, the CO anti‐poisoning of Sn‐Pt 3 Ga is improved with only 6.02% decay of the HOR activity after the CO poisoning, while Pt shows 44.7% decay.

Purified terephthalic acid (PTA), one kind of vital organic raw material widely used in polyester manufacturing, requires hydrogenation of 4-carboxybenzaldehyde (4-CBA) as a pivotal purification step. While Pd/C catalysts remain central to this process, their structure-activity relationship for the 4-CBA hydrogenation system is still unclear. In order to improve the performance of the Pd/C catalyst, this study systematically investigated the geometric effects of Pd nanoparticles on catalytic performance. Through controlled preparation of Pd/C catalysts with varied Pd nanoparticle structures, a direct correlation between nanoparticle morphology and catalytic activity in 4-CBA hydrogenation was established. Multiple characterization techniques were employed to determine geometric configurations of Pd nanoparticles, complemented by density functional theory (DFT) calculations to elucidate the reaction mechanism. The research results demonstrate a critical size-dependent structural transition in palladium (Pd) catalysts that directly correlates with hydrogenation performance. When the crystal size of Pd is <9 nm, the crystal morphology of Pd is ellipsoidal with the Pd(111) facet predominantly exposed, exhibiting enhanced activity and abundance of active sites that confer superior catalytic performance. Significantly, as the Pd nanoparticle size exceeds 9 nm, some Pd nanoparticles transform into truncated octahedral shapes with exposed mixed facets including Pd(111), Pd(100), Pd(210), and Pd(322). This structural evolution leads to a marked reduction in both the number and intrinsic activity of active sites, resulting in poor catalyst performance. This study elucidates the atomic-level structure-activity correlation in palladium-based catalytic systems, thereby paving the way for rational design of cost-effective catalyst architectures in industrial-scale PTA purification processes.

The development of advanced Co3O4-based electrocatalysts represents a critical pathway toward viable alternatives to noble metal oxides (e.g., IrO2, RuO2) for acidic oxygen evolution reactions (OER), thereby enabling the commercial viability of proton exchange membrane water electrolyzers (PEMWEs). In particular, the rational design of efficient and durable cobalt-based OER catalysts in acidic media by concurrently engineering surface electron transfer and interfacial water structure remains unexplored. Herein, combined with in situ X-ray absorption spectroscopy and theoretical calculations, we find that Nb incorporation stabilizes Co active sites via dynamic electron transfer under operando conditions, suppressing Co over-oxidation and dissolution. Moreover, Nb dopant with pronounced oxophilicity could enhance the *OH adsorption across the Co-Nb motifs, thereby leading to improved proportion of free-H2O in the electric-double-layer (EDL) region and lowered energy barrier for water dissociation, which are responsible for the improved acidic OER kinetics. As expected, the optimized Nb-Co3O4 catalyst delivers a low overpotential of 381 mV at 10 mA cm-2 in 0.5 M H2SO4. Remarkably, a PEMWE assembled with an Nb-Co3O4 anode needs a cell voltage of only 1.98 Vat 1.0 A cm-2 and stably operates over 430 h under 2 A cm-2, outperforming most reported Co-based catalysts. This work establishes a dual-strategy framework for designing adaptive electrocatalysts, where dynamic electronic interactions and interfacial engineering synergistically enable high activity and durability for industrial-scale PEMWE systems. (c) 2026 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

The origin of anode corrosion and its suppression in proton-exchange membrane water electrolysis remain debated because the mechanism of proton-coupled electron-transfer processes is unclear. In a recent issue of Nature Nanotechnology, Qiao and co-workers employ femtosecond electrochemical transient absorption spectroscopy to elucidate the corrosion mechanism of low-iridium anode catalysts and provide new insights into mitigating anode degradation.

Although cobalt spinel oxide-based catalysts have demonstrated promising performance for the oxygen evolution reaction in acid, strategies reported have largely focused on manipulating the binding energies of reaction intermediates through tailoring the inherent electronic structures. The role of interfacial water structures on the electrode surface in promoting the acidic oxygen evolution reaction performance through controlled water activation has been largely overlooked. Here we show that introducing chromium dopant into cobalt spinel oxide can simultaneously increase the activity and stability by promoting interfacial water dissociation and dynamic electron transfer. The chromium dopant can not only dynamically regulate the electronic structure of cobalt and mitigate the over-oxidation of active cobalt sites at high overpotential, but also enhance the coverage of hydroxyl species on the catalyst surface, thereby optimizing the interfacial water structure, accelerating the reactant free-water supply and promoting subsequent interfacial water dissociation. Consequently, the obtained catalyst demonstrates enhanced performance in both solution electrocatalysis and device electrocatalysis. This work provides a comprehensive understanding of enhancing the acidic oxygen evolution reaction performance by promoting interfacial water dissociation.

The development of highly efficient and stable RuO2-based electrocatalysts as promising alternatives to IrO2 for acidic oxygen evolution reaction (OER) is crucial for the practical application of proton exchange membrane water electrolyzers (PEMWEs). Although considerable efforts have been devoted to breaking the scaling relationship of adsorbate evolution mechanism (AEM) pathway through modulating the electronic structure of catalysts and the binding energies of reaction intermediate species, limited attention has been paid to the role of interfacial water structure at the interface between catalyst and electrolyte. Here, we anchored RuO2 onto oxophilic MoO3 nanosheet, and realized an optimized connectivity of hydrogen-bond network in the electric double layer (EDL). Through advanced in-situ spectroscopies, we demonstrate that the reconstructed interfacial water molecules can accelerate the dissociation and the follow-up proton transport across the interface, promoting a high-proton-flux interface that ensures simultaneous enhancement of both activity and stability. Consequently, the obtained RuO2/MoO3 heterojunction exhibits remarkable activity and stability in acidic OER (with an overpotential of 235 mV at a current density of 100 mA cm(-2) and excellent long-term durability of 420 hat 10 mA cm(-2)). When evaluated in a PEMWE device, it requires only 1.63 V to achieve a current density of 1.0 A cm(-2) and shows no significant voltage degradation over 500 h of continuous operation at a current density of 100 mA cm(-2).

ABSTRACT Hydrogen production through water electrolysis powered by renewable sources, particularly via proton exchange membrane water electrolysis (PEMWE), has garnered considerable interest due to its high efficiency and operational flexibility. However, the widespread adoption of this technology is primarily hindered by the intrinsically sluggish and complex reaction kinetics of the anodic acidic oxygen evolution reaction (OER). Contemporary research on high‐performance catalysts, including noble metal oxides and transition metal oxides, predominantly adopts a thermodynamic perspective, optimizing catalytic performance by modulating the adsorption energies of key reaction intermediates. However, this mainstream strategy frequently fails to adequately consider the actual electrochemical reaction environment, that is, the structured electric double layer at the electrode/electrolyte interface. The essence of electrocatalysis resides at the electrode–electrolyte interface, where the structure, orientation, and hydrogen‐bond network of interfacial water molecules critically influence water adsorption and activation, proton transfer, intermediate stabilization, and reaction pathway selection, thereby governing the overall reaction kinetics. This review focuses on acidic OER and systematically examines the central role of interfacial water throughout the catalytic process. We first clarify its function in different mechanistic pathways and introduce relevant in situ characterization techniques. Subsequently, we delve into the multiple roles of interfacial water, detailing its functions in participating as a reactant, stabilizing key intermediates, and regulating mass transport. Finally, we summarize recent strategies and design principles for enhancing catalyst performance through interfacial water structure engineering. This review delineates and consolidates the critical role of interfacial water structure, offering a new perspective for the rational design of efficient and stable acidic OER catalysts.