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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 Benefiting from ordered atomic structures and strong d‐orbital interactions, intermetallic compounds (IMCs) are promising electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, the body‐centered cubic IrGa IMCs with atomic donor–acceptor architectures are synthesized and anchored on the nitrogen‐doped reduced graphene oxide (i.e., IrGa/N‐rGO). Structural characterizations and theoretical calculations reveal that the electron‐rich Ir sites are atomically dispersed in IrGa/N‐rGO, facilitating the electron transfer between Ir atoms and adsorbed species, which can efficiently decrease the energy barriers of the potential determining step for both HER and OER. Impressively, the IrGa/N‐rGO||IrGa/N‐rGO exhibits excellent performance for overall water splitting in alkaline medium, requiring a low cell voltage of 1.51 V to achieve 10 mA cm −2 , meanwhile, exhibiting no significant degradation for 100 h. This work demonstrates that the rational design of noble metal electrocatalysts with donor–acceptor architectures is beneficial for catalytic reactions in energy conversion applications.

Abstract Developing highly efficient photocatalysts for converting CO2 into solar fuels is of great importance for energy sustainability. However, efficient photoreduction of CO2 over the heterogeneous catalyst is hindered by lack of precisely controlled active sites and poor contact between active sites and the semiconductor, which leads to low selectivity and poor photochemical stability of the catalyst. Herein, utilizing highly stable and readily tunable photoresponsive covalent triazine frameworks (CTFs) as intriguing platforms, the well-defined molecular catalysts are directly knitting into CTFs by an in-situ covalent-bonding strategy for the first time to afford photo-responsive single-site Ru CTFs. The robust chemical knitting of molecular catalyst with porous CTFs provides the atomically dispersed catalytic sites, providing enhanced light absorption and CO2 diffusion. Significantly, the resulting Ru-CTF can reduce CO2 to formic acid under visible light with excellent selectivity (98.5%) and activity (6270 μmol·gcat-1), which greatly outperforms most other polymer semiconductors reported so far. However, the homogeneous Ru counterpart (Ru(dcbpy)(CO)2Cl2, dcbpy=2,2'-bipyridine-5,5'-dicarbonitrile) exhibits a low activity and deactivates within 1 h. Systematic investigations reveal that the introduction of single sites (Ru-N2) can promote photoinduced charge separation and CO2 activation, thus significantly enhancing the photocatalytic performance. The combination of in-situ fourier transform infrared spectrometer (in-situ FTIR), density functional theory (DFT) calculations and luminescence quench experiments were particularly investigated to confirm the possible photocatalytic CO2 reduction mechanism over Ru-CTF. This work provides a new pathway and significant insights into the design of CTF-based single-site photocatalysts for highly selective CO2 photoreduction.

ABSTRACT The electrochemical reduction of carbon dioxide (CO 2 RR) to produce C 2+ products is extremely important. It serves as a crucial link in realizing efficient carbon cycle utilization and promoting sustainable energy development. Among various catalyst fields, copper‐based materials stand out. Their unique electronic and surface properties give them an advantage in selectively converting carbon dioxide into C 2+ compounds, thus attracting extensive research. However, challenges such as high overpotential, slow reaction kinetics, and low selectivity still persist. We analyzed various structural forms, ranging from single‐metal copper with tunable morphologies, to copper with different oxidation states, and then to copper‐doped diatomic single‐atom catalysts (DSACs). We discussed the design strategies of these three major categories of catalysts, systematically compared their catalytic performances and underlying mechanisms, and provided design insights for the further preparation of C 2+ products. Finally, the main challenges are outlined, the potential prospects of CO 2 RR are proposed, and it is hoped that large‐scale industrial applications can be achieved in the future.

Abstract Groundwater tidal response analysis is a valuable tool for monitoring leakage in groundwater systems, yet the interpretation of this response has often been incomplete. Notably, the impact of anisotropic aquifer permeability on tidal response has not been addressed in existing models. This study presents an analytical model to examine the effect of anisotropy on the tidal response of an aquifer overlain by a semi‐confined aquitard with finite storage. After verifying our model against previous models and numerical simulations, we fund: (a) At high vertical aquifer conductivity and aquitard leakage, the amplitude ratio of the tidal response is small, and the phase shift is positive, making our solution closely align with the existing leaky aquifer model. (b) As the vertical aquifer conductivity decreases, the amplitude ratio increases and the phase shift decreases and becomes negative at relatively low leakage, similar to that of a confined aquifer. (c) When the vertical aquifer conductivity is smaller relative to the horizontal one, the existing leaky aquifer model tends to underestimate the amplitude and overestimate the phase shift. (d) The aquitard storage has a significant effect on the tidal response of the aquifer when the aquitard leakage is large, but a negligible impact when the vertical aquifer conductivity is small. Applying our model to field data from four monitoring wells in the North China Plain, we find that when the shale content in the aquifer reaches 40.09%, our anisotropic model more effectively fits the observed phase shift compared to the existing leaky aquifer model.

Abstract While the ambient N 2 reduction to ammonia (NH 3 ) using H 2 O as hydrogen source (2N 2 +6H 2 O=4NH 3 +3O 2 ) is known as a promising alternative to the Haber–Bosch process, the high bond energy of N≡N bond leads to the extremely low NH 3 yield. Herein, we report a highly efficient catalytic system for ammonia synthesis using the low‐temperature dielectric barrier discharge plasma to activate inert N 2 molecules into the excited nitrogen species, which can efficiently react with the confined and concentrated H 2 O molecules in porous metal–organic framework (MOF) reactors with V 3+ , Cr 3+ , Mn 3+ , Fe 3+ , Co 2+ , Ni 2+ and Cu 2+ ions. Specially, the Fe‐based catalyst MIL‐100(Fe) causes a superhigh NH 3 yield of 22.4 mmol g −1 h −1 . The investigation of catalytic performance and systematic characterizations of MIL‐100(Fe) during the plasma‐driven catalytic reaction unveils that the in situ generated defective Fe−O clusters are the highly active sites and NH 3 molecules indeed form inside the MIL‐100(Fe) reactor. The theoretical calculation reveals that the porous MOF catalysts have different adsorption capacity for nitrogen species on different catalytic metal sites, where the optimal MIL‐100(Fe) has the lowest energy barrier for the rate‐limiting *NNH formation step, significantly enhancing efficiency of nitrogen fixation.

Abstract The photocatalytic activation of inert aromatic C─H bonds under mild conditions remains a major challenge due to the inherent stability of sp 2 C─H bonds and the lack of efficient, selective heterogeneous photocatalysts. Herein, by strategically balancing the solubility of aniline‐functionalized arsenic polyoxomolybdate (AsPOM) with the organic linker of 1,4‐bi(3‐dimethylamino‐1‐oxoprop‐2‐enyl)benzene (BDOEB), a new 3D covalent AsPOM‐organic polymer, termed POF‐2, was successfully prepared. Its short‐ to medium‐range ordered structure was resolved using the advanced total scattering atomic pair distribution function (PDF). The unique architecture of POF‐2 synergistically combines the strong oxidative capability of AsPOM with the tunable light absorption and oxygen activation ability of organic monomers, narrowing the bandgap from 3.13 eV (AsPOM) to 2.28 eV (POF‐2) and extending light absorption to 575 nm. Under ambient conditions with low‐energy visible‐light irradiation (10 W LED), POF‐2 exhibits exceptional photocatalytic performance in aromatic C─H bromination and [3+2] cycloaddition reactions, achieving >99% conversion and >99% selectivity. Mechanistic studies reveal that the well‐defined donor–acceptor (D–A) structure of POF‐2 facilitates rapid hole (h + )‐mediated C─H activation on AsPOM nodes and selective 1 O 2 generation on BDOEB linkers, avoiding nonproductive substrate mineralization. This work not only demonstrates a new 3D covalent AsPOM‐organic polymer for C─H functionalization but also provides a blueprint for designing molecularly precise, multifunctional photocatalysts for sustainable organic synthesis.

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 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.

Electrocatalysis. An s-block potassium single-atom electrocatalyst with K-N4 configuration derived from K+/polydopamine for efficient oxygen reduction is reported in the Research Article by Zhonglong Zhao, Jiangwei Zhang, Qin Wang, Limin Wu et al. (e202312409).

Abstract The excessive heat accumulation has been the greatest danger for chips to maintain the computing power. In this paper, a passive thermal management strategy for electronics cooling was developed based on the water vapor desorption process of the covalent organic frameworks (COFs). The precise regulation for the number of carbonyl group and the ratio of hydrophilicity and hydrophobicity within pore channels was achieved by water adsorption sites engineering. In particular, COF‐THTA with abundant water adsorption sites exhibited highest water uptake and desorption energy, which facilitate efficient cooling of electronics. In proof‐of‐concept testing, COF‐THTA coating (40×40 mm) provided a temperature drop of 7.5 °C in 25 minutes at a heating power of 937.5 W/m 2 , and remained stable after 10 intermittent heat cycles. Furthermore, the equivalent enthalpy of COF‐THTA coating can reach up to 1136 J/g coating . In real application scenarios, COF‐THTA coating improved the performance of two real computing devices by 26.73 % and 22.61 %, respectively. This strategy based on COFs provides a new thinking for passive thermal management, exhibiting great potential in efficient cooling of electronics.

Abstract The targeted construction of efficient CO 2 capture platforms for photocatalysis remains a significant challenge. Herein, we precisely engineered a proton clamp within a series of covalent organic frameworks (COFs) to function as CO 2 traps, thereby significantly enhancing the photocatalytic reduction of CO 2 to CO. The proton clamp was rationally designed by using an S‐shaped molecular motif featuring appropriate interatomic distances and strategically positioned protonation sites. Remarkably, the protonated COFs exhibited a superior CO production rate of 109 µmol g −1 h −1 in a gas‐solid reaction condition. The experimental and theoretical investigations confirmed that the proton clamp not only facilitated efficient CO 2 trapping but also rapidly delivered protons to the active sites, accelerating the reaction kinetics. This work provides molecular‐level insights into protonation strategies for optimizing photocatalytic CO 2 reduction, offering a new design principle for advanced COF‐based photocatalysts.

The challenges posed by environmental pollution, global warming resulting from carbon dioxide emissions, and energy scarcity jeopardize the sustainable progress of humanity. Prioritizing the advancement and sustainability of renewable energy sources is imperative to bolster global efforts promoting the displacement of fossil fuels and attaining carbon neutrality. Diverse material categories have been explored, encompassing potential applications in nitrogen reduction reactions, carbon dioxide reduction, water electrolysis, biomass conversion, and battery catalysis. These materials have undergone refinement through techniques like alloy synthesis, introduction of defects/dopants, and construction of heterostructures, resulting in significant enhancements. While many catalysts have demonstrated excellent catalytic performance in reactions such as nitrogen reduction, carbon dioxide reduction, water splitting, and biomass conversion, numerous questions regarding catalyst structure, active site functionality, and catalytic mechanisms remain unanswered. In this review, we summarize the progress of nanomaterials in energy catalytic conversion (The process where catalytic nanomaterials facilitate the conversion of energy carriers or small molecules into valuable products) of small molecules over the past five years, and systematically illustrate the characterization of nanomaterials in chemical reactions by X-ray absorption spectroscopy (XAS). Utilizing XAS technology to identify the active components of catalysts, track the dynamic structural evolution of catalysts, and observe stable reaction intermediates in transition metal single-atom catalysts, transition metal oxides, and metal polycrystals. XAS shows promising potential in various fields such as carbon reduction, nitrogen reduction, biomass conversion and porous materials, garnering widespread recognition in the catalysis community.