Tsz Woon Benedict Lo

Li-rich layered oxides (LLOs) are promising high-energy cathodes but suffer from irreversible oxygen redox and structural degradation associated with Li2MnO3 domains. Recently, disorder engineering has emerged as an effective strategy to regulate the local coordination environment and stabilize the oxygen redox of LLOs. Herein, we confirm the existence of intrinsic intralayer Li/Mn disorder within the Li2MnO3 domains, which can be classified into local Li-excess and TM-excess configurations derived from the initial Li-rich framework. Furthermore, DFT calculations suggest complementary local roles for the different disordered configurations: Li-excess domains promote oxygen redox activity, whereas TM-excess domains reinforce TM–O bonding and stabilize the framework against irreversible degradation. Consequently, M-LLO containing the coupled disordered configurations promotes more reversible anionic redox, suppresses irreversible oxygen release and transition-metal migration, and thereby delivers improved electrochemical stability. This work provides new insights into the role of intrinsic disorder regulation in Li-rich layered cathodes.

This review summarizes spin catalysis advances to guide rational catalyst design for energy conversion.

Structural ordering regulation via synthesis temperature dictates the structure, anionic redox, and electrochemistry of manganese-rich layered cathodes, while an optimized structural ordering degree enhances anionic redox and structural stability.

Structural dynamics in metal–organic frameworks (MOFs) typically rely on elaborate, flexible organic linkers. Here, we challenge this paradigm by demonstrating a rare, reversible 5‐phase‐transition cycle in a minimalist cobalt formate MOF system. Central to this evolution is the conceptual reframing of the amorphous state ( Co‐Amor ); rather than representing a structural dead‐end, Co‐Amor functions as a programmable, high‐energy reactive hub that lowers reorganization barriers. We show that specific guest molecules selectively direct the reconstruction of this amorphous matrix into distinct crystalline architectures, including chiral ( Co‐Hex ), perovskite‐like ( Co‐Trig ), diamondoid ( Co‐Mono1 ), and hydrated ( Co‐Mono2 ) frameworks, effectively ‘reprogramming’ the material's underlying lattice physics. The generality of the guest‐molecule selectivity is verified by Co‐Hex and Co‐Trig , which have different crystalline structures but share the same phase‐transition behavior, thereby further highlighting the adaptability and importance of this system. Most notably, we uncover a rare gas‐solid reconstruction where CO ₂ acts as a morphogenic trigger, inducing a gradual amorphous‐to‐crystal transition to the rigid Co‐Mono1 phase. This chemoselectivity originates from a specific C–H···O hydrogen‐bond complementarity between the formate channel walls and CO ₂ . This work highlights the untapped potential of amorphous intermediates in directing structural reconfigurations, offering a blueprint for designing highly adaptive materials from the simplest molecular building blocks.

Spin-state engineering has emerged as a powerful strategy for regulating the reactivity of single-atom catalysts (SACs) beyond conventional coordination and electronic structure optimization. In electrocatalytic NOx and COx conversion, many elementary steps involve open-shell intermediates, spin-dependent electron transfer, and radical-like transition states, making catalytic activity and selectivity highly sensitive to the spin configuration of the isolated metal centers. This Perspective introduces a spin-centered framework for SAC electrocatalysis in which spin polarization, spin crossover, and spin-selective orbital interactions govern access to spin-allowed pathways and stabilize key reaction intermediates. We first outline the fundamental spin-chemistry principles relevant to small-molecule activation, including spin selection rules, d-orbital occupation, spin polarization, and spin–orbit coupling. We then discuss how coordination environments, support interactions, adsorbate binding, electrochemical potentials, and external fields can be used to modulate the spin states of SACs under both static and operating conditions. Representative examples in NOx and COx electrocatalysis are highlighted to illustrate how spin-state engineering reshapes adsorption energetics, proton-coupled electron transfer, bond activation, and catalytic selectivity. Finally, we identify emerging opportunities in operando spin characterization, predictive electronic structure theory, and dynamically programmable catalyst design. By integrating spin chemistry with single-atom catalysis, this Perspective establishes the spin state as an active and programmable design parameter for next-generation electrocatalytic transformations.

The urgent need to mitigate accelerating CO₂ emissions has driven intense interest in photocatalytic CO₂ reduction (CO₂RR), a process that mimics natural photosynthesis to generate carbon-neutral, value-added chemicals. While efficiency has improved, the selective production of high-value C₂₊ products rather than C₁ compounds remains a critical challenge to economic viability. Single-atom catalysts offer promise for steering selectivity, yet how atomic-scale spatial distribution dictates reaction pathways remains poorly understood. Here, we demonstrate a programmed spatial distribution approach to induce synergistic cooperativity between neighboring Cu motifs within a UiO-67 matrix. By precisely modulating site distribution, we reveal a spatial threshold at which the framework transitions from isolated sites favoring C₁ products to correlated single-atom pairs (CSAPs) that facilitate C-C bond formation. Temperature-resolved electron paramagnetic resonance spectroscopy provides compelling evidence for the distribution-dependent proximity, capturing a unique magnetic feature that emerges as torsional linker motions are suppressed. This structural configuration utilizes the inherent rotational flexibility of the linkers to dynamically optimize interatomic distances, effectively stabilizing [OC-CO]* dimer intermediates and steering the reaction toward C₂ products.

The simultaneous and selective production of syngas and value-added chemicals from biomass-derived feedstocks is fundamentally restricted by sluggish multi-electron-proton transfer and the lack of precisely defined active sites capable of stabilizing reactive intermediates. Here, we report a sulfur-mediated coordination reconstruction strategy that transforms metastable rhenium species on two-dimensional chromium boride into uniformly dispersed Re-S₄ single atoms. The electronic environment of Re-S₄ optimizes the d-band center, stabilizing the key intermediate glyceraldehyde for selective C-C bond cleavage. In this work, the synergistic combination of atomic-scale engineering and reactant kinetics modulation yields a total syngas rate of 34.08 mmol g^-1 h^-1 with a wide-ranging tunable H₂/CO ratio (0.1 to 14.4), alongside a lactic acid yield of 90.8%. The system's robustness is further validated via large-scale outdoor sunlight-tracking tests, demonstrating its potential as a scalable, sustainable biorefinery technology for the concurrent production of gas-phase fuels and liquid-phase platform chemicals.

Photocatalytic reduction of O ₂ to H ₂ O ₂ is generally regarded to proceed through the *O ₂ hydrogenation pathway (*O ₂ → *OOH), which inevitably encounters a high energy barrier proton extraction process via cleavage of the H-O bond in H ₂ O. Designing a K and Cs co-modified polymeric carbon nitride (CN-KCs) to create dual-end adsorption sites as frustrated Lewis pairs for O ₂ , on which the O-O breaking energy is significantly reduced and a *O ₂ dissociation pathway towards photocatalytic H ₂ O ₂ synthesis is realized (*O ₂ → 2*O, then *O + *H ₂ O → H ₂ O ₂ ). The CN-KCs presents a competitive photocatalytic H ₂ O ₂ yield of 1806.6 μmolh ⁻¹ , a high quantum efficiency of 72.3% at 420 nm, and a solar-to-H ₂ O ₂ conversion efficiency of 6.1% with presence of biomass derivative. Here, we show that regulating dual-end adsorption sites opens a door to new *O ₂ dissociation avenue for efficient conversion of O ₂ to H ₂ O ₂ .

We demonstrate the sorption chemistry can be regulated by extra-framework counter-cations in metal–organic frameworks.

Spin-state plays a crucial role in defining the electronic structure and catalytic reactivity of transition metal catalysts. However, precise manipulation of spin states is challenging, and their impact on catalytic mechanisms remains poorly understood. Here, we show that the curvature of carbon nanotubes (CNTs) tunes the spin state of cobalt phthalocyanine (CoPc) anchored on CNTs, thereby affecting the activity and selectivity in the electroreduction of nitric oxide (NORR) to ammonia. As the CNT diameter falls below 3 nm, the Co²⁺ center spontaneously transitions from a low-spin (LS) to a high-spin (HS) state. Density functional theory calculations and in situ spectroscopic measurements show that the HS state weakens the N=O bond and promotes bent *NO, which favors NH₃ generation. As a result, the optimized catalyst achieves a high partial current density with a Faradaic efficiency of >90% at -0.5 V versus the reversible hydrogen electrode (RHE), while maintaining good stability. This work highlights spin-state engineering via support curvature for selective electrochemical transformations.