Polynary transition‐metal atom catalysts are promising to supersede platinum (Pt)‐based catalysts for oxygen reduction reaction (ORR). Regulating the local configuration of atomic catalysts is the key to catalyst performance enhancement. Different from the previously reported single‐atom or dual‐atom configurations, a new type of ternary‐atom catalyst, which consists of atomically dispersed, nitrogen‐coordinated Co–Co dimers, and Fe single sites (i.e., Co₂–N₆ and Fe–N₄ structures) that are coanchored on highly graphitized carbon supports is developed. This unique atomic ORR catalyst outperforms the catalysts with only Co₂–N₆ or Fe–N₄ sites in both alkaline and acid conditions. Density functional theory calculations clearly unravels the synergistic effect of the Co₂–N₆ and Fe–N₄ sites, which can induce higher filling degree of Fe–d orbitals and favors the binding capability to *OH intermediates (the rate determining step). This ternary‐atom catalyst may be a promising alternative to Pt to drive the cathodic ORR in zinc–air batteries.

Although Ti₃C₂T_x MXene is a promising material for many applications such as catalysis, energy storage, electromagnetic interference shielding due to its metallic conductivity and high processability, it’s poor resistance to oxidation at high temperatures makes its application under harsh environments challenging. Here, we report an air-stable Ti₃C₂T_x based composite with extracted bentonite (EB) nanosheets. In this case, oxygen molecules are shown to be preferentially adsorbed on EB. The saturated adsorption of oxygen on EB further inhibits more oxygen molecules to be adsorbed on the surface of Ti₃C₂T_x due to the weakened p-d orbital hybridization between adsorbed O₂ and Ti₃C₂T_x, which is induced by the Ti₃C₂T_x/EB interface coupling. As a result, the composite is capable of tolerating high annealing temperatures (above 400 °C for several hours) both in air or humid environment, indicating highly improved antioxidation properties in harsh condition. The above finding is shown to be independent on the termination ratio of Ti₃C₂T_x obtained through different synthesis routes. Utilized as terahertz shielding materials, the composite retains its shielding ability after high-temperature treatment even up to 600 °C, while pristine Ti₃C₂T_x is completely oxidized with no terahertz shielding ability. Joule heating and thermal cycling performance are also demonstrated.

The surface and interface chemistry are of significance on controlling the properties of two-dimensional transition metal carbides and nitrides (MXenes). Numerous efforts have been devoted to the regulation of Ti₃C₂T_x MXene, however, tuning interlayer spacing and surface halogen termination of other MXenes (besides Ti₃C₂T_x) is rarely reported while demanded. Here we propose a Lewis-basic halides treatment, which is capable of simultaneously engineering the interlayer spacing and surface termination of various MXenes. Benefited from the abundant desolvated halogen anions and cations in molten state Lewis-basic halides, the -F termination was substituted by nucleophilic reaction and the interlayer spacing was enlarged. Ti₃C₂T_x MXene treated by this method showed a high specific capacity of 229 mAh g⁻¹ for Li⁺ storage, which is almost 2 times higher than pristine one. Considering the universality, our method provides an approach to regulating the properties of MXenes, which may expand their potential applications in energy storage, optoelectronics and beyond.

Renewable electricity-powered CO evolution from CO₂emissions is a promising first step in the sustainable production of commodity chemicals, but performing electrochemical CO₂reduction economically at scale is challenging since only noble metals, for example, gold and silver, have shown high performance for CO₂-to-CO. Cu is a potential catalyst to achieve CO₂reduction to CO at the industrial scale, but the C-C coupling process on Cu significantly depletes CO* intermediates, thus limiting the CO evolution rate and producing many hydrocarbon and oxygenate mixtures. Herein, we tune the CO selectivity of Cu by alloying a second metal Sb into Cu, and report an antimony-copper single-atom alloy catalyst (Sb₁Cu) of isolated Sb-Cu interfaces that catalyzes the efficient conversion of CO₂-to-CO with a Faradaic efficiency over 95%. The partial current density reaches 452 mA cm⁻²with approximately 91% CO Faradaic efficiency, and negligible C₂₊products are observed. In situ spectroscopic measurements and theoretical simulations reason that the atomic Sb-Cu interface in Cu promotes CO₂adsorption/activation and weakens the binding strength of CO*, which ends up with enhanced CO selectivity and production rates.