Abstract The development of efficient direct air capture (DAC) systems coupled with photocatalytic CO 2 conversion is still an appealing challenge. Here, we engineered a series of defective Cu 3 ‐based metal–organic frameworks (Cu 3 ‐MOFs) for integrated atmospheric CO 2 capture and in situ photoreduction. The defective Cu 3 ‐MOFs were constructed through selective removal of coordinated CO 3 2− from pristine MOFs with HCl etching, generating unsaturated Cu active sites for CO 2 harvesting, and the Cu 3 ‐MOFs demonstrated enhanced CO 2 capture kinetics and capacity that compared to their pristine counterpart. Remarkably, the captured CO 2 could be directly photoreduced to C 2 H 4 with an optimal production rate of 18.25 µmol·g −1 ·h −1 without additional photosensitizer or sacrificial agent. The experimental and theoretical results revealed that the defective sites not only facilitated CO 2 adsorption but also promoted C–C coupling of *CO intermediates, thereby enhancing C 2 H 4 production. This work provides deep insights for designing advanced materials toward direct air‐to‐fuel conversion.

An unprecedented molecular pumping cassette was designed and implemented for the construction of molecular necklaces, that is, radial [n]catenanes. The mechanism was fully confirmed on a model [2]pseudorotaxane, and the novel clipping-followed-by-pumping strategy was used to prepare a series of [n]catenanes (n = 2–5). A pair of [3]catenane diastereomers sequentially threaded with two different wheels was also accomplished. The success of utilizing molecular pumping to construct molecular necklaces offers new insights into complex molecular architectures and expands the application of molecular machines in synthesis.

Abstract Elucidating the synergistic catalytic mechanism between multiple active centers is of great significance for heterogeneous catalysis; however, finding the corresponding experimental evidence remains challenging owing to the complexity of catalyst structures and interface environment. Here we construct an asymmetric TeN 2 –CuN 3 double-atomic site catalyst, which is analyzed via full-range synchrotron pair distribution function. In electrochemical CO 2 reduction, the catalyst features a synergistic mechanism with the double-atomic site activating two key molecules: operando spectroscopy confirms that the Te center activates CO 2 , and the Cu center helps to dissociate H 2 O. The experimental and theoretical results reveal that the TeN 2 –CuN 3 could cooperatively lower the energy barriers for the rate-determining step, promoting proton transfer kinetics. Therefore, the TeN 2 –CuN 3 displays a broad potential range with high CO selectivity, improved kinetics and good stability. This work presents synthesis and characterization strategies for double-atomic site catalysts, and experimentally unveils the underpinning mechanism of synergistic catalysis.

Abstract Bismuth vanadate (BiVO 4 ) has been widely investigated as a photocatalyst or photoanode for solar water splitting, but its activity is hindered by inefficient cocatalysts and limited understanding of the underlying mechanism. Here we demonstrate significantly enhanced water oxidation on the particulate BiVO 4 photocatalyst via in situ facet-selective photodeposition of dual-cocatalysts that exist separately as metallic Ir nanoparticles and nanocomposite of FeOOH and CoOOH (denoted as FeCoO x ), as revealed by advanced techniques. The mechanism of water oxidation promoted by the dual-cocatalysts is experimentally and theoretically unraveled, and mainly ascribed to the synergistic effect of the spatially separated dual-cocatalysts (Ir, FeCoO x ) on both interface charge separation and surface catalysis. Combined with the H 2 -evolving photocatalysts, we finally construct a Z-scheme overall water splitting system using [Fe(CN) 6 ] 3−/4− as the redox mediator, whose apparent quantum efficiency at 420 nm and solar-to-hydrogen conversion efficiency are optimized to be 12.3% and 0.6%, respectively.

Highly efficient La/Sr-based perovskites with surface Fe sites and Sr vacancies were developed for the active lattice oxygen mechanism (LOM) of the oxygen evolution reaction (OER), and a relationship between the LOM and dynamic surface structure was established.

Abstract Complex metal nanoparticles distributed uniformly on supports demonstrate distinctive physicochemical properties and thus attract a wide attention for applications. The commonly used wet chemistry methods display limitations to achieve the nanoparticle structure design and uniform dispersion simultaneously. Solid-phase synthesis serves as an interesting strategy which can achieve the fabrication of complex metal nanoparticles on supports. Herein, the solid-phase synthesis strategy is developed to precisely synthesize uniformly distributed CoFe@FeO x core@shell nanoparticles. Fe atoms are preferentially exsolved from CoFe alloy bulk to the surface and then be carburized into a Fe x C shell under thermal syngas atmosphere, subsequently the formed Fe x C shell is passivated by air, obtaining CoFe@FeO x with a CoFe alloy core and a FeO x shell. This strategy is universal for the synthesis of MFe@FeO x (M = Co, Ni, Mn). The CoFe@FeO x exhibits bifunctional effect on regulating polysulfides as the separator coating layer for Li-S and Na-S batteries. This method could be developed into solid-phase synthetic systems to construct well distributed complex metal nanoparticles.

Metal ion substitution and anion exchange are two effective strategies for regulating the electronic and geometric structure of spinel. However, the optimal location of foreign metallic cations and the exact role of these metals and anions remain elusive. Herein, CoFe2O4-based hollow nanospheres with outstanding oxygen evolution reaction activity are prepared by Cr3+ substitution and S2– exchange. X-ray absorption spectra and theoretical calculations reveal that Cr3+ can be precisely doped into octahedral (Oh) Fe sites and simultaneously induce Co vacancy, which can activate adjacent tetrahedral (Td) Fe3+. Furthermore, S2– exchange results in structure distortion of Td-Fe due to compressive strain effect. The change in the local geometry of Td-Fe causes the *OOH intermediate to deviate from the y-axis plane, thus enhancing the adsorption of the *OOH. The Co vacancy and S2– exchange can adjust the geometric and electronic structure of Td-Fe, thus activating the inert Td-Fe and improving the electrochemical performance.

The protonation process of adsorbed *CO intermediates has been widely recognized as a critical determinant governing product selectivity in electrocatalytic carbon dioxide reduction reaction (eCO 2 RR). However, the active hydrogen species and mechanism of *CO protonation in acid eCO 2 RR remain ambiguous. Particularly, the involvement of H + in *CO hydrogenation is still under debate. Here, we developed a CuCl-mediated synthesis strategy integrated with rare-earth doping electronic structure engineering, which enriches intermediates and promotes adsorbed hydrogen (*H) participation in reactions, respectively. For the first time, differential electrochemical mass spectrometry (DEMS) and nuclear magnetic resonance (NMR) were employed to clarify the participation of hydrogen species in liquid and gaseous eCO 2 RR products, with isotope labeling utilized to distinguish the distribution of H + and *H in the products. Experimental verification confirmed that in acidic electrolytes, the ethylene pathway was dominated by H + hydrogenation, whereas the ethanol pathway incorporated contributions from both H + and *H. Upon yttrium (Y) doping into Cu 2 O/CuCl, interfacial water activation was markedly enhanced, thereby enabling the provision of supplementary *H for catalytic engagement. Notably, our Y-Cu 2 O/CuCl catalyst achieves a remarkable 65.7% Faradaic efficiency for ethanol with exceptional 65-h stability at 200 mA cm −1 . This work provides new evidence for H + participation in acid eCO 2 RR, emphasizing the critical role of H 2 O activation degree in selectivity regulation, and thus offering novel insights for designing efficient acid eCO 2 RR catalysts.

Abstract Currently, single‐atom catalysts (SACs) research mainly focuses on transition metal atoms as active centers. Due to their delocalized s/p‐bands, the s‐block main group metal elements are typically regarded as catalytically inert. Herein, an s‐block potassium SAC (K−N−C) with K‐N 4 configuration is reported for the first time, which exhibits excellent oxygen reduction reaction (ORR) activity and stability under alkaline conditions. Specifically, the half‐wave potential ( E 1/2 ) is up to 0.908 V, and negligible changes in E 1/2 are observed after 10,000 cycles. In addition, the K−N−C offers an exceptional power density of 158.1 mW cm −2 and remarkable durability up to 420 h in a Zn‐air battery. Density functional theory (DFT) simulations show that K−N−C has bifunctional active K and C sites, can optimize the free energy of ORR reaction intermediates, and adjust the rate‐determining steps. The crystal orbital Hamilton population (COHP) results showed that the s orbitals of K played a major role in the adsorption of intermediates, which was different from the d orbitals in transition metals. This work significantly guides the rational design and catalytic mechanism research of s‐block SACs with high ORR activity.

In recent years, the depletion risk of fossil fuels has driven increasing interest in renewable energy. Among various technologies, Proton Exchange Membrane Fuel Cells (PEMFCs) stand out due to their fast startup and high power density. However, the commonly used Nafion membranes suffer from reduced proton conductivity under low humidity and high temperatures, limiting their practical application. Polyoxometalates (POMs), with their excellent proton conductivity and thermal stability, have emerged as promising alternatives. Yet, their high water solubility raises safety concerns, and their water-dependent conduction mechanisms and structure-function relationships remain insufficiently understood. These issues hinder the practical development of POM-based proton conductors. This paper presents a comprehensive review of the key properties and proton conduction mechanisms of POMs, with a particular focus on POM crystals and their composites exhibiting high proton conductivity. Representative studies are analyzed to elucidate design strategies, structure-function relationships, and recent research progress over the past five years. Finally, perspectives and recommendations are proposed to inform future research directions and promote practical applications in the field of proton-conducting materials.

ABSTRACT This article is a response to the comment “Reassessing Machine Learning Techniques for Electrocatalyst Design: A Call for Robust Methodologies”. First, we clarify that the artificial neural network–SHapley Additive exPlanation (ANN–SHAP) method mentioned in the comment originates from the original work of Ding et al., which we only briefly summarized. In that study, nine different machine learning models were employed to predict the performance of proton exchange membrane fuel cells, among which the ANN model performed best. SHAP, together with multiple interpretability techniques (PDP, Tree‐based Rule, EIX, etc.), was used to cross‐validate feature importance, which was further compared with the results from manual feature selection, PCA, and t‐distributed stochastic neighbor embedding, and complemented by experimental validation to reduce the risk of bias amplification. We agree with the commenter that model interpretability should be approached with caution, as the absence of a definitive “ground truth” for feature importance remains a current challenge. However, benchmarking SHAP explanations against domain knowledge or validating them using synthetic datasets can help reduce the risk of misinterpretation. Regarding the unsupervised methods suggested in the comment (FA and HVGS), we consider them to have exploratory value for certain data structures, but caution is needed when applying them to experimental systems involving nonlinearity or high noise.

Regular hollow mesoporous superparticles with an opening window and controllable surface grooves can significantly improve the high-loading performance of aqueous zinc ion hybrid capacitors, but their synthesis remains a great challenge. Herein, an electrostatic force-assisted monomicelle confined assembly strategy is demonstrated for synthesizing such regular mesoporous hollow superparticles. The mesoporous superparticles feature a hollow (∼250 nm) in the center and a tailored transverse window (35–50 nm) to enable the superparticles to be totally connected from the inner to external surface, and a monolayer of spherical mesopores (∼15 nm) is arrayed in an orderly fashion on the hollow shell to form the unique crisscrossed grooves. Notably, an accurate manipulation in the width (29.5–62.4 nm), depth (2.1–40.7 nm), and number in the horizontal and vertical (11 × 11–5 × 5) grooves can be realized. Finally, the mesoporous superparticles as the high-loading electrodes in aqueous zinc ion hybrid capacitors exhibit a weak polarization, a high specific capacity (205 mAh g,–1 at 0.1 A g–1), and an excellent rate performance (105 mAh g–1 at 10 A g–1). The adjustability of surface grooves enables the orthogonal control of the charge transfer rate and ion diffusion rate. The mesoporous superstructures demonstrate the potential for energy storage applications in different environments.

A bimetallic MOF, CoMg-TCPP, is reported for the photocatalytic reduction of carbon dioxide to formic acid.

Abstract We explored a co‐dissolved strategy to embed mono‐dispersed Pt center into V 2 O 5 support via dissolving [PtV 9 O 28 ] 7− into [V 10 O 28 ] 6− aqueous solution. The uniform dispersion of [PtV 9 O 28 ] 7− in [V 10 O 28 ] 6− solution allows [PtV 9 O 28 ] 7− to be surrounded by [V 10 O 28 ] 6− clusters via a freeze‐drying process. The V centers in both [PtV 9 O 28 ] 7− and [V 10 O 28 ] 6− were converted into V 2 O 5 via a calcination process to stabilize Pt center. These double separations can effectively prevent the Pt center agglomeration during the high‐temperature conversion process, and achieve 100 % utilization of Pt in [PtV 9 O 28 ] 7− . The resulting Pt‐V 2 O 5 single‐atom‐site catalysts exhibit a CH 4 yield of 247.6 μmol g −1 h −1 , 25 times higher than that of Pt nanoparticle on the V 2 O 5 support, which was accompanied by the lactic acid photooxidation to form pyruvic acid. Systematical investigations on this unambiguous structure demonstrate an important role of Pt−O atomic pair synergy for highly efficient CO 2 photoreduction.