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Topological defects are inevitable existence in carbon‐based frameworks, but their intrinsic electrocatalytic activity and mechanism remain under‐explored. Herein, the hydrogen evolution reaction (HER) of pentagonal carbon‐rings is probed by constructing pentagonal ring‐rich carbon (PRC), with optimized electronic structures and higher HER activity relative to common hexagonal carbon (HC). Furthermore, to improve the reactivity, we couple Ru clusters with PRC (Ru@PRC) through p‐d orbital hybridization between C and Ru atoms, which drives a shortcut transfer of electrons from Ru clusters to pentagonal rings. The electron‐deficient Ru species leads to a notable negative shift in d‐band centers of Ru and weakens their binding strength with hydrogen intermediates, thus enhancing the HER activity in different pH media. Especially, at a current density of 10 mA cm−2, PRC greatly reduces alkaline HER overpotentials from 540 to 380 mV. And Ru@PRC even exhibits low overpotentials of 28 and 275 mV to reach current densities of 10 and 1000 mA cm−2, respectively. Impressively, the mass activity and price activity of Ru@PRC are 7.83 and 15.7 times higher than that of Pt/C at the overpotential of 50 mV. Our data unveil the positive HER reactivity of pentagonal defects and good application prospects. [ABSTRACT FROM AUTHOR]

The development of oxygen evolution reaction (OER) electrocatalyst for seawater electrolysis plays a crucial role in producing renewable hydrogen energy. However, during the seawater electrolysis process, the anode inevitably undergoes chloride oxidation reaction (ClOR) due to Cl− adsorption, making the seawater electrolysis process difficult to sustain. Inspired by the selective permeability of cell membranes, we propose a biomimetic design of frustrated Lewis pairs (FLPs) layers for selective seawater oxidation. Combining experimental results and molecular dynamics simulations, it has been demonstrated that cerium dioxide layers with FLPs sites can decompose water molecules, capture hydroxyl anions, and repel chloride ions simultaneously. DFT theoretical analysis indicates that the FLP sites regulate the Ce 4 f−O 2p−Ni 3d gradient orbital coupling, providing additional oxygen non‐bonding (ONB) to stabilize the Ni−O bond and optimize the adsorption strength of intermediates, thereby breaking the *OH and *OOH scaling relationship. The assembled anion exchange membrane electrolyzers exhibit an efficiency of 95.7 % at a current density of 0.1 A cm−2 and can stably operate for 250 hours at a current density of 0.2 A cm−2. [ABSTRACT FROM AUTHOR]

Electrochemical reduction reactions, as cathodic processes in many energy‐related devices, significantly impact the overall efficiency determined mainly by the performance of electrocatalysts. Metal–organic frameworks (MOFs) derived carbon‐supported metal materials have become one of star electrocatalysts due to their tunable structure and composition through ligand design and metal screening. However, for different electroreduction reactions, the required active metal species vary in phase component, electronic state, and catalytic center configuration, hence requiring effective customization. From this perspective, this review comprehensively analyzes the structural design principles, metal loading strategies, practical electroreduction performance, and complex catalytic mechanisms, thereby providing insights and guidance for the future rational design of such electroreduction catalysts. [ABSTRACT FROM AUTHOR]

Recently, hydrogen spillover based binary (HSBB) catalysts have received widespread attention due to the sufficiently utilized reaction sites. However, the specific regulation mechanism of spillover intensity is still unclear. Herein, we have fabricated oxygen vacancies enriched Ru/NiMoO4‐x to investigate the internal relationship between electron supply and mechanism of hydrogen spillover enhancement. The DFT calculations cooperate with in situ Raman spectrum to uncover that the H* spillover from NiMoO4‐x to Ru. Meanwhile, oxygen vacancies weakened the electron supply from Ru to NiMoO4‐x, which contributes to dilute the resistance of built‐in electric field (BEF) for hydrogen spillover. In addition, the higher ion concentration in electrolyte will promote the H* adsorption step obviously, which is demonstrated by in situ EIS tests. As a result, the Ru/NiMoO4‐x exhibits a low overpotential of 206 mV at 3.0 A cm−2, a small Tafel slope of 28.8 mV dec−1, and an excellent durability of 550 h at the current density of 0.5 A cm−2 for HER in 1.0 M KOH seawater. [ABSTRACT FROM AUTHOR]

Despite the intriguing potential shown by Sn‐based perovskite oxides in CO2 electroreduction (CO2RR), the rational optimization of their CO2RR properties is still lacking. Here we report an effective strategy to promote CO2‐to‐HCOOH conversion of Sn‐based perovskite oxides by A‐site‐radius‐controlled Sn−O bond lengths. For the proof‐of‐concept examples of Ba1−xSrxSnO3, as the A‐site cation average radii decrease from 1.61 to 1.44 Å, their Sn−O bonds are precisely shortened from 2.06 to 2.02 Å. Our CO2RR measurements show that the activity and selectivity of these samples for HCOOH production exhibit volcano‐type trends with the Sn−O bond lengths. Among these samples, the Ba0.5Sr0.5SnO3 features the optimal activity (753.6 mA ⋅ cm−2) and selectivity (90.9 %) for HCOOH, better than those of the reported Sn‐based oxides. Such optimized CO2RR properties could be attributed to favorable merits conferred by the precisely controlled Sn−O bond lengths, e.g., the regulated band center, modulated adsorption/activation of intermediates, and reduced energy barrier for *OCHO formation. This work brings a new avenue for rational design of advanced Sn‐based perovskite oxides toward CO2RR. [ABSTRACT FROM AUTHOR]

Theoretical calculations unveil that the formation of Os‐OsSe2 heterostructures with neutralized work function (WF) perfectly balances the electronic state between strong (Os) and weak (OsSe2) adsorbents and bidirectionally optimizes the hydrogen evolution reaction (HER) activity of Os sites, significantly reducing thermodynamic energy barrier and accelerating kinetics process. Then, heterostructural Os‐OsSe2 is constructed for the first time by a molten salt method and confirmed by in‐depth structural characterization. Impressively, due to highly active sites endowed by the charge balance effect, Os‐OsSe2 exhibits ultra‐low overpotentials for HER in both acidic (26 mV @ 10 mA cm−2) and alkaline (23 mV @ 10 mA cm−2) media, surpassing commercial Pt catalysts. Moreover, the solar‐to‐hydrogen device assembled with Os‐OsSe2 further highlights its potential application prospects. Profoundly, this special heterostructure provides a new model for rational selection of heterocomponents. [ABSTRACT FROM AUTHOR]

We report an effective strategy to enhance CO2 electroreduction (CER) properties of Cu‐based Ruddlesden–Popper (RP) perovskite oxides by engineering their A‐site cation deficiencies. With La2−xCuO4‐δ (L2−xC, x=0, 0.1, 0.2, and 0.3) as proof‐of‐concept catalysts, we demonstrate that their CER activity and selectivity (to C2+ or CH4) show either a volcano‐type or an inverted volcano‐type dependence on the x values, with the extreme point at x=0.1. Among them, at −1.4 V, the L1.9C delivers the optimal activity (51.3 mA cm−2) and selectivity (41.5 %) for C2+, comparable to or better than those of most reported Cu‐based oxides, while the L1.7C exhibits the best activity (25.1 mA cm−2) and selectivity (22.1 %) for CH4. Such optimized CER properties could be ascribed to the favorable merits brought by the cation‐deficiency‐induced oxygen vacancies and/or CuO/RP hybrids, including the facilitated adsorption/activation of key reaction species and thus the manipulated reaction pathways. [ABSTRACT FROM AUTHOR]

To overcome the current limitations of chemodynamic therapy (CDT), a Mo2C‐derived polyoxometalate (POM) is readily synthesized as a new CDT agent. It permits synergistic chemodynamic and photothermal therapy operating in the second near‐infrared (NIR‐II) biological transparent window for deep tissue penetration. POM aggregated in an acidic tumor micro‐environment (TME) whereby enables specific tumor targeting. In addition to the strong ability to produce singlet oxygen (1O2) presumably via Russell mechanism, its excellent photothermal conversion enhances the CDT effect, offers additional tumor ablation modality, and permits NIR‐II photoacoustic imaging. Benefitting from the reversible redox property of molybdenum, the theranostics based on POM can escape from the antioxidant defense system. Moreover, combining the specific responsiveness to TME and localized laser irradiation, side‐effects shall be largely avoided. [ABSTRACT FROM AUTHOR]