Oxygen reduction reaction (ORR) kinetics are closely related to the electronic structure of active sites. Herein, a single‐atomic Mn catalyst decorated with adjacent MoP nanocrystals (MoP@MnSAC‐NC) is reported. The decoration of MoP drives the electronic structure transition of Mn sites from low‐spin to high‐spin states through an electronic phosphide‐support interaction. The rearranged electron occupation in 3dxz‐yz and 3dz2 orbitals of Mn sites leads to electrons occupying the σ orbital in Mn─*O2, thereby favoring O2 adsorption to initiate the ORR mechanism. In situ characterizations confirm that Mn 3dz2 orbital occupation state can activate molecular O₂ and optimize the adsorption of the *OOH intermediate. As a result, the MoP@MnSAC‐NC displays an outstanding alkaline ORR half‐wave potential (E1/2 = 0.894 V), excellent peak power densities (173/83 mW cm−2 for liquid/solid‐state Zn‐air batteries, respectively), and long‐term stability (840 h) superior to commercial Pt/C. This work provides profound insights into spintronics‐level engineering, guiding the design of next‐generation high‐performance ORR catalysts.
Single-atom catalysts (SACs) have emerged as transformative materials in heterogeneous electrocatalysis, yet their conventional symmetric coordination environments often yield suboptimal catalytic efficacy. This review systematically examines the deliberate disruption of local symmetry as a powerful design strategy to precisely tailor the electronic properties of SACs. We categorize and analyze atomic-level modulation approaches, including strain-induced lattice distortion, defect-engineered coordination tailoring, and curvature-derived interfacial fields, demonstrating how these strategies effectively break the intrinsic symmetry of motifs such as M–N4. Our analysis reveals that such symmetry breaking redistributes electron density around the metal center, lifts orbital degeneracy, and optimizes the d-band center, leading to enhanced intermediate adsorption, accelerated reaction kinetics, and broken scaling relationships. Furthermore, these asymmetrically configured SACs exhibit improved stability through strengthened metal–support interactions. While significant progress has been made, we conclude that future efforts must address the challenges of atomic-level precision, stability under operation, and scalable synthesis to fully realize the potential of symmetry-broken SACs across various electrocatalytic applications, thereby establishing a new paradigm for the rational design of advanced electrocatalytic materials.
Ammonia and nitric acid, versatile industrial feedstocks, and burgeoning clean energy vectors hold immense promise for sustainable development. However, Haber–Bosch and Ostwald processes, which generates carbon dioxide as massive by-product, contribute to greenhouse effects and pose environmental challenges. Thus, the pursuit of nitrogen fixation through carbon–neutral pathways under benign conditions is a frontier of scientific topics, with the harnessing of solar energy emerging as an enticing and viable option. This review delves into the refinement strategies for scale-up mild photocatalytic nitrogen fixation, fields ripe with potential for innovation. The narrative is centered on enhancing the intrinsic capabilities of catalysts to surmount current efficiency barriers. Key focus areas include the in-depth exploration of fundamental mechanisms underpinning photocatalytic procedures, rational element selection, and functional planning, state-of-the-art experimental protocols for understanding photo-fixation processes, valid photocatalytic activity evaluation, and the rational design of catalysts. Furthermore, the review offers a suite of forward-looking recommendations aimed at propelling the advancement of mild nitrogen photo-fixation. It scrutinizes the existing challenges and prospects within this burgeoning domain, aspiring to equip researchers with insightful perspectives that can catalyze the evolution of cutting-edge nitrogen fixation methodologies and steer the development of next-generation photocatalytic systems.
The interaction between water molecules and surfaces in porous carbon‐based materials plays a significant role in various fields including but not limited to catalysis, gas sorption, or electrochemical energy storage and conversion. The incorporation of nitrogen enhances the hydrophilicity of typically rather nonpolar carbon‐based materials but the molecular understanding of water chemical configuration in such porous materials remains incomplete. Water adsorption on nitrogen‐containing nanoporous carbon surfaces is governed by a subtle balance between water–water and water–surface hydrogen bonding interactions, which together determine the water structures formed and their stability. In this work, in situ Scanning Transmission X‐ray microscopy performed on individual nanoporous carbon particles under a humid atmosphere is used to elucidate the interactions between nitrogen‐containing carbon surfaces and water molecules. The hydrogen bonding of water is found to be nonuniform within the particles and to depend on the nanopore size and the chemical bonding of nitrogen atoms. The nature of the nitrogen sites interacting with water is further characterized by resonance inelastic X‐ray Scattering and near ambient pressure X‐ray Photoelectron Spectroscopy. This study provides new perspectives on water interaction when confined in nanoporous nitrogen‐rich carbons.
18 April 2026 in Angewandte Chemie International Edition