Yahui Cheng

Sn oxides are promising CO ₂ RR electrocatalysts for formate production, but their high activity is difficult to sustain because cathodic reconstruction can over‐reduce active oxide‐derived surfaces to metallic Sn. This dynamic evolution makes it challenging to identify and stabilize the true working‐state active phase. Here, we construct a descriptor‐guided framework that links dynamic Sn‐oxide reconstruction with electronic‐structure evolution and formate‐producing activity to identify and stabilize the favorable working‐state active phase. Electronic‐structure analysis shows that the optimal Sn _x O _y /Sn surface stabilizes the *OCHO intermediate through coupled charge‐polarization redistribution and Sn 5 s /5 p orbital modulation. To quantify this effect, we develop a TD descriptor integrating Bader charge, Sn 5 p coupling, and Sn 5 s lone‐pair activation, which exhibits a volcano‐type correlation with the limiting free energy, with the minimum at TD = 0.67 corresponding to the most favorable reconstructed Sn _x O _y /Sn surface. Guided by this descriptor, amorphous SnO ₂ is designed to stabilize the favorable Sn _x O _y /Sn working state and suppress deep reduction, achieving an HCOO ⁻ partial current density of 438.0 mA cm ⁻² at −1.8 V vs. RHE, 1.8 times that of commercial SnO ₂ . This work provides a descriptor‐guided strategy for stabilizing reconstructed active phases in CO ₂ RR.

Electrochemical water electrolysis for hydrogen production offers a feasible way for renewable energy development but still faces significant challenges. Developing high-performance catalysts with high activity, low cost, long-term stability, corrosion resistance, and antisediment aggregation is crucial for the practical application of water electrolysis, particularly seawater electrolysis. For this purpose, we designed a Ni(Fe)P/Ni(Fe)OOH/MXene composite electrocatalyst on an iron foam substrate, which uses a multi-interface structure, Fe self-doping, and incomplete phosphating to jointly adjust the electronic structure and optimize H* absorption. Importantly, the incorporation of MXene significantly enhances electrical conductivity, increases the exposure sites, and facilitates gas release, thereby boosting the hydrogen evolution reaction (HER) performance. Meanwhile, the self-doping of the substrate and vertically staggered nanosheet morphology induced by MXene are utilized to enhance the bonding between the catalyst and substrate, as well as the antisediment aggregation performance, thereby achieving long-term stable operation in an alkaline seawater environment. Consequently, the catalyst demonstrates outstanding HER behavior, achieving 100 mA cm–2 at 140 mV in freshwater and 165 mV in seawater, while maintaining stability for 45 h. Moreover, Ni(Fe)P/Ni(Fe)OOH/MXene was assembled with Fe-Ni(OH)2 into a dual-electrode electrolysis cell, achieving 10 mA cm–2 at only 1.49 V in freshwater, and 1.56 V in natural seawater. This work may open up a prospect for freshwater electrolysis of high efficiency HER catalyst.

Spin-polarized charge transfer plays a critical role in the oxygen evolution reaction (OER), yet its underlying mechanism remains elusive. Here, first-principles calculations reveal that OER on 2D ferromagnetic Fe₃GeTe₂ predominantly follows a dual-site mechanism with cooperative active sites, owing to its substantially reduced overpotential (0.34 V vs 0.80 V for the single-site route) and modest O-O coupling barrier (0.68 eV). Tensile strain further enhances the OER activity of Fe₃GeTe₂, reducing the key O-O coupling barrier to 0.45 eV at 5% strain, maintaining the dual-site mechanism preference. Mechanistic analysis shows that the OER on Fe₃GeTe₂ proceeds through a spin-selective charge transfer process. Unlike the single-site route that requires spin-flip at the rate-determining step, the dual-site mechanism maintains consistent spin alignment throughout all four electron transfers, enabling rapid O-O bond formation. Essentially, tensile strain strengthens the spin polarization of Fe₃GeTe₂ at the Fermi level, promoting electron transfer through favorable spin states and generating highly spin-polarized oxygen intermediates that facilitate spin-triplet O₂ formation. These findings uncover a spin-selective charge transfer mechanism that simultaneously lowers thermodynamic and kinetic barriers, offering fundamental insights for the rational design of spin-polarized OER electrocatalysts.

Electrochemical CO ₂ reduction reaction (CO ₂ RR) in acidic electrolyte enables high single‐pass carbon efficiency (SPCE), while highly corrosive acidic electrolytes typically cause catalyst degradation. It is reported that the dealloying of Cu/Ag and Cu/Al alloys, as well as the increased C─C coupling energy barrier, are reasons that advances in neutral/alkaline electrolysis do not translate to acidic conditions. Detailed characterizations reveal the dynamic evolution of the alloy in acidic CO ₂ RR, that is Cu ₂₉ Ag ₇₁ undergoes dealloying, re‐deposition, and surface restructuration, ultimately forming the stable Ag/Cu interfacial structure. In situ Raman spectroscopy reveals the dynamic evolution of interfacial water structures on Cu ₂₉ Ag ₇₁ during acidic CO ₂ RR and also indicates that the evolved interface structure enhances the proton activity for CO ₂ RR. Cu ₂₉ Ag ₇₁ achieves a CO Faradaic efficiency (FE) of 93.1% with stable electrolysis of 45 h at 250 mA cm ⁻² . Based on this stable, high CO‐selective catalyst, a tandem electrode is designed by deploying it on the Cu ₉₀ Al ₁₀ surface to act as a protective and CO overflow layer. The tandem configuration suppresses dealloying in Cu ₉₀ Al ₁₀ and creates a localized alkaline environment, thereby promoting C─C coupling. This tandem electrode exhibits a multi‐carbon FE of 81.2% at 648 mA cm ⁻² , a SPCE of 70.4%, and stable electrolysis of 30 h.

Tensile strain enhances the ferroelectric phase stability and ferromagnetic transition temperature of 2D multiferroic CuCrP ₂ X ₆ (X = S, Se) monolayers, providing ideal candidates for non-volatile memory devices.

The electrochemical co-reduction of carbon dioxide (CO₂) and nitrate (NO₃ ⁻) to urea presents a sustainable strategy to alleviate the ecological and food crisis. However, the current urea electrosynthesis faces low selectivity issues due to the high energy barrier of C–N coupling, as well as the unbalanced supply of key intermediates. Herein, we report that a Au-doped Cu bimetallic catalyst effectively balances the supply of C-containing and N-containing intermediates, thereby enhancing urea selectivity. In situ Raman spectroscopy and density functional theory calculations demonstrate that doping Au into Cu enhances the surface coverage of the *CO intermediate and optimizes the adsorption energy of *NO, thereby lowering the energy barrier of C–N coupling from 0.44 eV on the Cu surface to 0.15 eV on the Cu–Au surface. Meanwhile, this doping engineering also suppresses the reactions competing with urea electrosynthesis. As a result, the Cu–Au catalyst achieves a urea faradaic efficiency of 67.81% and a yield rate of 49.34 μmol cm⁻² h⁻¹ at −0.4 V versus the reversible hydrogen electrode.