Hydrogen Spillover Phenomenon at the Interface of Metal-Supported Electrocatalysts for Hydrogen Evolution.

ConspectusHydrogen spillover, as a well-known phenomenon for thermal hydrogenation, generally involves the migration of active hydrogen on the surface of metal-supported catalysts. For thermocatalytic hydrogenation, hydrogen spillover generally takes place from metals with superiority for dissociating hydrogen molecules to supports with strong hydrogen adsorption under a H2 environment with high pressures. The former can bring high hydrogen chemical potential to largely reduce the kinetic barrier of the migration of active hydrogen species from metals to supports. At the same time, the latter can make H* migration thermodynamically spontaneous. For these reasons, hydrogen spillover is a common interfacial phenomenon occurring on metal-supported catalysts during thermocatalysis. Recently, this phenomenon has been observed for the exceptionally enhanced electrocatalytic performance for hydrogen evolution and other electrocatalytic organic synthesis. Different from hydrogen spillover for thermocatalysis under high H2 pressure, hydrogen spillover for electrocatalysis involves the migration of active hydrogen species (H*) from metals with strong hydrogen adsorption to supports with weak hydrogen adsorption, thereby suffering from a thermodynamically unfavorable process accompanied by a high kinetic barrier. Thus, the occurrence of hydrogen spillover at the electrocatalytic interface is not easy, and successful cases are rare. Understanding the underlying nature of hydrogen spillover at the electrocatalytic interface of metal-supported catalysts is critical to the rational design of advanced electrocatalysts.In this Account, we provide in-depth insights into recent advances in hydrogen spillover at the electrocatalytic interface for a significantly enhanced hydrogen evolution performance. Electron accumulation at the metal-support interface induces severe interfacial H* trapping and is recognized as the main factor in the failed hydrogen spillover. Given this, we developed two novel strategies to promote the occurrence of hydrogen spillover at the electrocatalytic interface. These strategies include (i) the introduction of ligand environments to enrich the local hydrogen coverage on metals and lower the barrier for interfacial hydrogen spillover and (ii) the minimization of work function difference between metals and supports (ΔΦ) to relieve electron accumulation and lower the kinetic barrier for hydrogen spillover. Also, we summarize the previously reported strategy of shortening the metal-support interface distance to lower the kinetic barrier for interfacial hydrogen spillover. Afterward, some criteria and methodologies are proposed to identify the hydrogen spillover phenomenon at the electrocatalytic interface. Finally, the remaining challenges and future perspectives are also discussed. Based on this Account, we aim to provide new insights into electrocatalysis, particularly the targeted control of hydrogen spillover at the electrocatalytic interface, and then to offer guidelines for the rational design of advanced electrocatalysts.

Tandem Electrocatalytic Alkyne Semihydrogenation over Bicomponent Catalysts through Hydrogen Spillover.

Electrocatalytic alkyne semihydrogenation under mild conditions is a more attractive approach for alkene production than industrial routes but suffers from either low production efficiency or high energy consumption. Here, we describe a tandem catalytic concept that overcomes these challenges. Component (i), which can trap hydrogen effectively, is partnered with component (ii), which can readily release hydrogen for hydrogenation, to enable efficient generation of active hydrogen on component (i) at low overpotentials and timely (i)-to-(ii) hydrogen spillover and facile desorptive hydrogenation on component (ii). We examine this concept over bicomponent palladium-copper catalysts for the production of representative 2-methyl-3-butene-2-ol (MBE) from 2-methyl-3-butyne-2-ol (MBY) and achieve a record high MBE production rate of 1.44 mmol h-1 cm-2 and a Faraday efficiency of ~88.8 % at a low energy consumption of 1.26 kWh kgMBE -1. With these catalysts, we further achieve 60 h continuous production of MBE with record high profit space.

Covalently Bonded Ni Sites in Black Phosphorene with Electron Redistribution for Efficient Metal-Lightweighted Water Electrolysis.

The metal-lightweighted electrocatalysts for water splitting are highly desired for sustainable and economic hydrogen energy deployments, but challengeable. In this work, a low-content Ni-functionalized approach triggers the high capability of black phosphorene (BP) with hydrogen and oxygen evolution reaction (HER/OER) bifunctionality. Through a facile in situ electro-exfoliation route, the ionized Ni sites are covalently functionalized in BP nanosheets with electron redistribution and controllable metal contents. It is found that the as-fabricated Ni-BP electrocatalysts can drive the water splitting with much enhanced HER and OER activities. In 1.0 M KOH electrolyte, the optimized 1.5 wt% Ni-functionalized BP nanosheets have readily achieved low overpotentials of 136 mV for HER and 230 mV for OER at 10 mA cm-2. Moreover, the covalently bonding between Ni and P has also strengthened the catalytic stability of the Ni-functionalized BP electrocatalyst, stably delivering the overall water splitting for 50 h at 20 mA cm-2. Theoretical calculations have revealed that Ni-P covalent binding can regulate the electronic structure and optimize the reaction energy barrier to improve the catalytic activity effectively. This work confirms that Ni-functionalized BP is a suitable candidate for electrocatalytic overall water splitting, and provides effective strategies for constructing metal-lightweighted economic electrocatalysts.

Cold to Hot: Tumor Immunotherapy by Promoting Vascular Normalization Based on PDGFB Nanocomposites.

Immunotherapy is a promising cancer therapeutic strategy. However, the "cold" tumor immune microenvironment (TIME), characterized by insufficient immune cell infiltration and immunosuppressive status, limits the efficacy of immunotherapy. Tumor vascular abnormalities due to defective pericyte coverage are gradually recognized as a profound determinant in "cold" TIME establishment by hindering immune cell trafficking. Recently, several vascular normalization strategies by improving pericyte coverage have been reported, whereas have unsatisfactory efficacy and high rates of resistance. Herein, a combinatorial strategy to induce tumor vasculature-targeted pericyte recruitment and zinc ion-mediated immune activation with a platelet-derived growth factor B (PDGFB)-loaded, cyclo (Arg-Gly-Asp-D-Phe-Lys)-modified zeolitic imidazolate framework 8 (PDGFB@ZIF8-RGD) nanoplatform is proposed. PDGFB@ZIF8-RGD effectively induced tumor vascular normalization, which facilitated trafficking and infiltration of immune effector cells, including natural killer (NK) cells, M1-like macrophages and CD8+ T cells, into tumor microenvironment. Simultaneously, vascular normalization promoted the accumulation of zinc ions inside tumors to trigger effector cell immune activation and effector molecule production. The synergy between these two effects endowed PDGFB@ZIF8-RGD with superior capabilities in reprogramming the "cold" TIME to a "hot" TIME, thereby initiating robust antitumor immunity and suppressing tumor growth. This combinatorial strategy for improving immune effector cell infiltration and activation is a promising paradigm for solid tumor immunotherapy.

Bioinspired porous three-coordinated single-atom Fe nanozyme with oxidase-like activity for tumor visual identification via glutathione.

Inspired by structures of natural metalloenzymes, a biomimetic synthetic strategy is developed for scalable synthesis of porous Fe-N3 single atom nanozymes (pFeSAN) using hemoglobin as Fe-source and template. pFeSAN delivers 3.3- and 8791-fold higher oxidase-like activity than Fe-N4 and Fe3O4 nanozymes. The high catalytic performance is attributed to (1) the suppressed aggregation of atomically dispersed Fe; (2) facilitated mass transfer and maximized exposure of active sites for the created mesopores by thermal removal of hemoglobin (2 ~ 3 nm); and (3) unique electronic configuration of Fe-N3 for the oxygen-to-water oxidation pathway (analogy with natural cytochrome c oxidase). The pFeSAN is successfully demonstrated for the rapid colorimetric detection of glutathione with a low limit of detection (2.4 nM) and wide range (50 nM-1 mM), and further developed as a real-time, facile, rapid (~6 min) and precise visualization analysis methodology of tumors via glutathione level, showing its potentials for diagnostic and clinic applications.

Regulation of frustrated Lewis pairs on CeO2 facilitates tandem transformation of styrene and CO2.

The frustrated Lewis pair (FLP) site of (Ce, Ce)-O on the CeO2(110) surface undergoes reconstruction to form (La, Ce)-O upon La-doping. The FLP site of (La, Ce)-O with the tailored local Lewis acid-base property and increased spatial distance between the Lewis acid and base facilitates the tandem transformation of styrene and CO2 through the weakened adsorption of CO2 while maintaining activation.

Enlarging the Ni-O Bond Polarizability in a Phosphorene-Hosted Metal-Organic Framework for Boosted Water Oxidation Electrocatalysis.

The emerging lattice-oxygen oxidation mechanism (LOM) presents attractive opportunities for breaking the scaling relationship to boost oxygen evolution reaction (OER) with the direct OLattice-*O interaction. However, currently the LOM-triggering rationales are still debated, and a streamlined physicochemical paradigm is extremely desirable for the design of LOM-defined OER catalysts. Herein, a Ni metal-organic framework/black phosphorene (NiMOF/BP) heterostructure is theoretically profiled and constructed as a catalytic platform for the LOM-derived OER studies. It is found that the p-type BP host can enlarge the Ni-O bond polarizability of NiMOF through the Ni-O bond stretching and Ni valence declining synergically. Such an enlarged bond polarizability will in principle alleviate the lattice oxygen confinement to benefit the LOM pathway and OER performance. As a result, the optimized NiMOF/BP catalyst exhibits promising OER performance with a low overpotential of 260 mV at 10 mA cm-2 and long-term stability in 1 M KOH electrolyte. Both experiment and calculation results suggest the activated LOM pathway with a more balanced step barrier in the NiMOF/BP OER catalyst. This research puts forward Ni-O bond polarizability as the criterion to design LOM-scaled electrocatalysts for water oxidation.

Platinum and Frustrated Lewis Pairs on Ceria as Dual-Active Sites for Efficient Reverse Water-Gas Shift Reaction at Low Temperatures.

The low-temperature reverse water-gas shift (RWGS) reaction faces the following obstacles: low activity and unsatisfactory selectivity. Herein, the dual-active sites of platinum (Pt) clusters and frustrated Lewis pair (FLP) on porous CeO2 nanorods (Ptcluster /PN-CeO2 ) provide an interface-independent pathway to boost high performance RWGS reaction at low temperatures. Mechanistic investigations illustrate that Pt clusters can effectively activate and dissociate H2 . The FLP sites, instead of the metal and support interfaces, not only enhance the strong adsorption and activation of CO2 , but also significantly weaken CO adsorption on FLP to facilitate CO release and suppress the CH4 formation. With the help of hydrogen spillover from Pt to PN-CeO2 , the Ptcluster /PN-CeO2 catalysts achieved a CO yield of 29.6 %, which is very close to the thermodynamic equilibrium yield of CO (29.8 %) at 350 °C. Meanwhile, the Ptcluster /PN-CeO2 catalysts delivered a large turnover frequency of 8720 h-1 . Moreover, Ptcluster /PN-CeO2 operated stably and continuously for at least 840 h. This finding provides a promising path toward optimizing the RWGS reaction.

Electrochemical Etching Switches Electrocatalytic Oxygen Evolution Pathway of IrOx /Y2 O3 from Adsorbate Evolution Mechanism to Lattice-Oxygen-Mediated Mechanism.

Oxygen evolution reaction (OER) plays key roles in electrochemical energy conversion devices. Recent advances have demonstrated that OER catalysts through lattice oxygen-mediated mechanism (LOM) can bypass the scaling relation-induced limitations on those catalysts through adsorbate evolution mechanism (AEM). Among various catalysts, IrOx , the most promising OER catalyst, suffers from low activities for its AEM pathway. Here, it is demonstrated that a pre-electrochemical acidic etching treatments on the hybrids of IrOx and Y2 O3 (IrOx /Y2 O3 ) switch the AEM-dominated OER pathway to LOM-dominated one in alkali electrolyte, delivering a high performance with a low overpotential of 223 mV at 10 mA cm-2 and a long-term stability. Mechanism investigations suggest that the pre-electrochemical etching treatments create more oxygen vacancies in catalysts due to the dissolution of yttrium and then provide highly active surface lattice oxygen for participating OER, thereby enabling the LOM-dominated pathway and resulting in a significantly increased OER activity in basic electrolyte.

Rhenium Suppresses Iridium (IV) Oxide Crystallization and Enables Efficient, Stable Electrochemical Water Oxidation.

IrO2 as benchmark electrocatalyst for acidic oxygen evolution reaction (OER) suffers from its low activity and poor stability. Modulating the coordination environment of IrO2 by chemical doping is a methodology to suppress Ir dissolution and tailor adsorption behavior of active oxygen intermediates on interfacial Ir sites. Herein, the Re-doped IrO2 with low crystallinity is rationally designed as highly active and robust electrocatalysts for acidic OER. Theoretical calculations suggest that the similar ionic sizes of Ir and Re impart large spontaneous substitution energy and successfully incorporate Re into the IrO2 lattice. Re-doped IrO2 exhibits a much larger migration energy from IrO2 surface (0.96 eV) than other dopants (Ni, Cu, and Zn), indicating strong confinement of Re within the IrO2 lattice for suppressing Ir dissolution. The optimal catalysts (Re: 10 at%) exhibit a low overpotential of 255 mV at 10 mA cm-2 and a high stability of 170 h for acidic OER. The comprehensive mechanism investigations demonstrate that the unique structural arrangement of the Ir active sites with Re-dopant imparts high performance of catalysts by minimizing Ir dissolution, facilitating *OH adsorption and *OOH deprotonation, and lowering kinetic barrier during OER. This study provides a methodology for designing highly-performed catalysts for energy conversion.

Reduction of Reactive Oxygen Species Accumulation Using Gadolinium-Doped Ceria for the Alleviation of Atherosclerosis.

Atherosclerosis is a common cardiovascular disease with increasing morbidity and mortality. The pathogenesis of atherosclerosis is strongly related to endothelial dysfunction, which is induced by severe oxidative stress damage derived from reactive oxygen species (ROS). Thus, ROS plays a critical role in the pathogenesis and progression of atherosclerosis. In this work, we demonstrated that the gadolinium doping of CeO2 (Gd/CeO2) nanozymes as effective ROS scavengers delivered high performance for antiatherosclerosis. It was found that the chemical doping of Gd promoted the surface proportion of Ce3+ in the nanozymes and thereby enhanced the overall ROS scavenging ability. In vitro and in vivo experiments unambiguously showed that the Gd/CeO2 nanozymes efficiently scavenged harmful ROS at the cellular and histological levels. Further, Gd/CeO2 nanozymes were demonstrated to significantly reduce vascular lesions by reducing lipid accumulation in macrophage and decreasing inflammatory factor levels, thereby inhibiting the exacerbation of atherosclerosis. Moreover, Gd/CeO2 can serve as T1-weighted magnetic resonance imaging contrast agents, which can generate sufficient contrast to distinguish the location of plaque during living imaging. Through those efforts, Gd/CeO2 may serve as a potential diagnostic and treatment nanomedicine for the ROS-induced atherosclerosis.

Reductive damage induced autophagy inhibition for tumor therapy.

Numerous therapeutic anti-tumor strategies have been developed in recent decades. However, their therapeutic efficacy is reduced by the intrinsic protective autophagy of tumors. Autophagy plays a key role in tumorigenesis and tumor treatment, in which the overproduction of reactive oxygen species (ROS) is recognized as the direct cause of protective autophagy. Only a few molecules have been employed as autophagy inhibitors in tumor therapy to reduce protective autophagy. Among them, hydroxychloroquine is the most commonly used autophagy inhibitor in clinics, but it is severely limited by its high therapeutic dose, significant toxicity, poor reversal efficacy, and nonspecific action. Herein, we demonstrate a reductive-damage strategy to enable tumor therapy by the inhibition of protective autophagy via the catalytic scavenging of ROS using porous nanorods of ceria (PN-CeO2) nanozymes as autophagy inhibitor. The antineoplastic effects of PN-CeO2 were mediated by its high reductive activity for intratumoral ROS degradation, thereby inhibiting protective autophagy and activating apoptosis by suppressing the activities of phosphatidylinositide 3-kinase/protein kinase B and p38 mitogen-activated protein kinase pathways in human cutaneous squamous cell carcinoma. Further investigation highlighted PN-CeO2 as a safe and efficient anti-tumor autophagy inhibitor. Overall, this study presents a reductive-damage strategy as a promising anti-tumor approach that catalytically inhibits autophagy and activates the intrinsic antioxidant pathways of tumor cells and also shows its potential for the therapy of other autophagy-related diseases. Electronic Supplementary Material: Supplementary material (cellular uptake of PN-CeO2, effects of PN-CeO2 on several common malignant tumor models, viability of HaCaT cells treated with PN-CeO2 at different concentrations, time-dependent body-weight curves of SCL-1 tumor-bearing nude mice, the biodistribution of Ce element in main tissues and tumors after injection of PN-CeO2, measurement of Ce element concentration in urine and feces samples, H&E-stained images of main organs, and measurement of liver and kidney function in mice after different treatment) is available in the online version of this article at 10.1007/s12274-022-5139-z.

Insights into the Effect of Catalytic Intratumoral Lactate Depletion on Metabolic Reprogramming and Immune Activation for Antitumoral Activity.

Lactate, a characteristic metabolite of the tumor microenvironment (TME), drives immunosuppression and promotes tumor progression. Material-engineered strategies for intratumoral lactate modulations demonstrate their promise for tumor immunotherapy. However, understanding of the inherent interconnections of material-enabled lactate regulation, metabolism, and immunity in the TME is scarce. To address this issue, urchin-like catalysts of the encapsulated Gd-doped CeO2 , syrosingopine, and lactate oxidase are used in ZIF-8 (USL, where U, S, and L represent the urchin-like Gd-doped CeO2 @ZIF-8, syrosingopine, and lactate oxidase, respectively) and orthotopic tumor models. The instructive relationships of intratumoral lactate depletion, metabolic reprogramming, and immune activation for catalytic immunotherapy of tumors is illustrated. The catalysts efficiently oxidize intratumoral lactate and significantly promote tumor cell apoptosis by in situ-generated ·OH, thereby reducing glucose supply and inducing mitochondrial damage via lactate depletion, thus reprogramming glycometabolism. Subsequently, such catalytic metabolic reprogramming evokes both local and systemic antitumor immunity by activating M1-polarizaed macrophages and CD8+ T cells, leading to potent antitumor immunity. This study provides valuable mechanistic insights into material-interfered tumor therapy through intratumoral lactate depletion and consequential connection with metabolic reprogramming and immunity remodeling, which is thought to enhance the efficacy of immunotherapy.

Sustainable production of hydrogen with high purity from methanol and water at low temperatures.

Carbon neutrality initiative has stimulated the development of the sustainable methodologies for hydrogen generation and safe storage. Aqueous-phase reforming methanol and H2O (APRM) has attracted the particular interests for their high gravimetric density and easy availability. Thus, to efficiently release hydrogen and significantly suppress CO generation at low temperatures without any additives is the sustainable pursuit of APRM. Herein, we demonstrate that the dual-active sites of Pt single-atoms and frustrated Lewis pairs (FLPs) on porous nanorods of CeO2 enable the efficient additive-free H2 generation with a low CO (0.027%) through APRM at 120 °C. Mechanism investigations illustrate that the Pt single-atoms and Lewis acidic sites cooperatively promote the activation of methanol. With the help of a spontaneous water dissociation on FLPs, Pt single-atoms exhibit a significantly improved reforming of *CO to promote H2 production and suppress CO generation. This finding provides a promising path towards the flexible hydrogen utilizations.

Insights on catalytic mechanism of CeO2 as multiple nanozymes.

CeO2 with the reversible Ce3+/Ce4+ redox pair exhibits multiple enzyme-like catalytic performance, which has been recognized as a promising nanozyme with potentials for disease diagnosis and treatments. Tailorable surface physicochemical properties of various CeO2 catalysts with controllable sizes, morphologies, and surface states enable a rich surface chemistry for their interactions with various molecules and species, thus delivering a wide variety of catalytic behaviors under different conditions. Despite the significant progress made in developing CeO2-based nanozymes and their explorations for practical applications, their catalytic activity and specificity are still uncompetitive to their counterparts of natural enzymes under physiological environments. With the attempt to provide the insights on the rational design of highly performed CeO2 nanozymes, this review focuses on the recent explorations on the catalytic mechanisms of CeO2 with multiple enzyme-like performance. Given the detailed discussion and proposed perspectives, we hope this review can raise more interest and stimulate more efforts on this multi-disciplinary field.

Photoinduced Phase Transition of Ce-UiO-66 to Ce-BDC-OH.

External stimuli-responsive phase transition of metal-organic frameworks (MOFs) introduces intriguing functions for diverse applications under practical settings. Herein, we reported a phase transition from cubic Ce-UiO-66 to triclinic Ce-BDC-OH under light irradiation. Such a phase transition underwent a ligand-to-metal charge transfer process, which was unambiguously revealed by Fourier transform infrared spectroscopy, nuclear magnetic resonance, electron paramagnetic resonance, etc. We proposed a phase transition mechanism through (1) the photoreduction of the metal core from Ce4+ into Ce3+; (2) the photogeneration of •OH and hydroxylation of BDC into BDC-OH; and (3) the carboxylate migration and lattice rearrangement for transitions. The phenomenon of the Ce4+-to-Ce3+ reduction also enables a diamagnetism-to-paramagnetism transition, suggesting its potential as a photostimulus-responsive magnetic switch.

Phytate Coordination-Enhanced Electrocatalytic Activity of Copper for Nitroarene Hydrogenation through Concerted Proton-Coupled Electron Transfer.

Coupling acid-electrolyte proton exchange membrane fuel cells for electricity generation and cathodic hydrogenation for valuable chemical production shows great potential in energy and chemical industry. The key for this promising approach is the identification of cathode electrocatalysts with acid resistance, high activity, and low fabrication cost for practical applications. Among various promising cathodic candidates for this integrative approach, the easily available and cheap Cu suffers from low acidic hydrogenation activity due to kinetically arduous proton adsorption/activation. Inspired by the kinetic advantages of the concerted proton-coupled electron transfer (CPET) over the sequential proton-electron transfer process, herein, we use phytate coordination on Cu surface to overcome the kinetic bottleneck for proton adsorption/activation through the CPET pathway in an acidic half-cell setup; this leads to 1 order of magnitude activity enhancement (36.94-fold) for nitrobenzene hydrogenation. Mechanistic analysis confirms that phytate, as proton acceptor, induces the CPET process and overcomes the above kinetic limitations by tuning the d-band center and concentrating protons on the Cu surface. Consequently, the CPET process facilitates the formation of active hydrogen intermediates for efficient cathodic hydrogenation. This work provides a promising approach to integrate electricity generation and chemical production.

Phytic acid-modified CeO2 as Ca2+ inhibitor for a security reversal of tumor drug resistance.

Ca2+ plays critical roles in the development of diseases, whereas existing various Ca regulation methods have been greatly restricted in their clinical applications due to their high toxicity and inefficiency. To solve this issue, with the help of Ca overexpressed tumor drug resistance model, the phytic acid (PA)-modified CeO2 nano-inhibitors have been rationally designed as an unprecedentedly safe and efficient Ca2+ inhibitor to successfully reverse tumor drug resistance through Ca2+ negative regulation strategy. Using doxorubicin (Dox) as a model chemotherapeutic drug, the Ca2+ nano-inhibitors efficiently deprived intracellular excessive free Ca2+, suppressed P-glycoprotein (P-gp) expression and significantly enhanced intracellular drug accumulation in Dox-resistant tumor cells. This Ca2+ negative regulation strategy improved the intratumoral Dox concentration by a factor of 12.4 and nearly eradicated tumors without obvious adverse effects. Besides, nanocerias as pH-regulated nanozyme greatly alleviated the adverse effects of chemotherapeutic drug on normal cells/organs and substantially improved survivals of mice. We anticipate that this safe and effective Ca2+ negative regulation strategy has potentials to conquer the pitfalls of traditional Ca inhibitors, improve therapeutic efficacy of common chemotherapeutic drugs and serves as a facile and effective treatment platform of other Ca2+ associated diseases. Electronic Supplementary Material: Supplementary material (further details of the XRD pattern of CeO2, TEM images, XPS spectra, cellular uptake study, cytotoxicity data, apoptosis study, biodistribution, and biosecurity of nanocerias in vivo, etc.) is available in the online version of this article at 10.1007/s12274-022-4069-0.

Insights into the Interfacial Lewis Acid-Base Pairs in CeO2 -Loaded CoS2 Electrocatalysts for Alkaline Hydrogen Evolution.

Despite the known efficacy of CeO2 as a promoter in alkaline hydrogen evolution reaction (HER), the underlying mechanism of this effect remains unclear. CoS2 , a pyrite-type alkaline HER electrocatalyst, suffers from sluggish HER kinetics and severe catalyst leaching due to its weak water dissociation kinetics and oxygen-related corrosion. Herein, it is demonstrated that the interfacial Lewis acid-base Ce∙∙∙S pairs in CeO2 -loaded CoS2 effectively improve the catalytic activity and durability. In CeO2 -loaded CoS2 nanowire array electrodes, these interfacial Lewis acid-base Ce∙∙∙S pairs with unique electronic and structural configurations efficiently activate water adsorptive dissociation and kinetically accelerate hydrogen evolution, delivering a low overpotential of 36 mV at 10 mA cm-2 in alkaline media. Such Ce∙∙∙S pairs also weaken O2 adsorption on CoS2 , leading to undecayed activity over 1000 h. These findings are expected to provide guidance for the design of CeO2 -based electrocatalysts as well as other hybrid electrocatalysts for water splitting.