Meng Zhang

Biomass provides renewable carbon for the production of fuels, chemicals, and functional materials

The dynamic nature of single‐atom catalysts, manifested as transient coordination fluctuations during individual molecular turnovers, has provided crucial mechanistic insights. However, the practical exploitation of such molecular‐level dynamics remains fundamentally challenging due to their experimental elusiveness and poor controllability. Here, we report a paradigm shift from these stochastic fluctuations to programmable coordination switching, enabled by the operando‐reversible reconstruction of single‐atom Cu sites in a Pt/bpy‐UiO‐CuX ₂ model catalyst. Triggered by a reductive environment during hydrogenation, a metastable N ₂ ‐Cu‐H configuration is generated under reducing conditions and remains the dominant Cu state during catalysis, before reversibly converting to an oxidized Cu‐(OH) ₂ form after depletion of reducing species and air exposure. Meanwhile, the coordination anions can be reprogrammed through external acid/anion environments, enabling interconversion among Cl ⁻ , OH ⁻ , and sulfate‐containing Cu coordination states. Multimodal operando spectroscopy combined with theoretical calculations demonstrates that the N ₂ ‐Cu‐H intermediate modulates the electronic state of the active Pt center, thereby boosting phenylacetylene‐to‐styrene selectivity by simultaneously lowering styrene desorption energy by 0.68 eV while raising the barrier for styrene hydrogenation by 0.66 eV. This work elevates dynamic single‐atom sites from stochastic structural fluctuations to programmable coordination switching, establishing a new paradigm for enzyme‐mimetic catalysts with adaptive responsiveness to redox and acid–base environments.

A CuRu/Al ₂ O ₃ bimetallic catalyst exhibits 99.9% FAL conversion and 99.9% FA selectivity under mild conditions. The Cu–Ru synergy not only enhances the activation of H ₂ but also effectively promotes the hydrogenation of the CO bond.

With the rapid industrialization, excessive reliance on fossil fuels has resulted in energy crises and environmental pollution, driving the search for sustainable alternatives. Biomass-derived resources have emerged as promising candidates to replace fossil-based feedstocks. Among these, furfural (FF) serves as a key platform molecule that can be catalytically hydrogenated to various high-value chemicals, with furfuryl alcohol (FA) representing one of the most valuable products. Currently, Cr-based catalysts remain predominant for the selective hydrogenation of FF to FA. However, the severe environmental toxicity of Cr necessitates urgent development of alternative Cr-free catalytic systems. This study systematically reviews recent advances in FF hydrogenation to FA, providing an in-depth discussion of reaction mechanisms, including adsorption configurations, solvent effects, and side reactions, as well as a comprehensive analysis of structure–activity relationships, involving active metal, support, promoter, and preparation methods. Furthermore, we evaluate the application of the advanced characterization techniques for monitoring the reaction processes. Finally, we propose the future research directions: (1) designing efficient and stable non-noble metal catalysts and (2) elucidating reaction mechanisms via the combined in situ characterization and theoretical calculations. These efforts would facilitate the academic understanding and industrial implementation of the FF-to-FA conversion process.

Dry reforming of methane (DRM) is an effective strategy to simultaneously convert CH₄ and CO₂ into valuable syngas. However, the widely employed Ni-based catalysts often suffer from rapid deactivation due to metal sintering and deposited carbon under harsh conditions. Herein, Ni/Ce_0.2Zr_0.8O₂ catalysts were synthesized using the evaporation-induced self-assembly (EISA) method with the addition of the triblock copolymer surfactant P123. The addition of an appropriate amount of P123 improved the Ni dispersion; reduced Ni particle size; and enhanced the activation efficiency of both CH₄ and CO₂, thus increasing the reaction rate. In addition, the addition of P123 also enhanced the surface basicity and increased the concentration of oxygen vacancies of the catalyst, which enhanced its carbon removal capability and reduced deposited carbon. The catalyst with 0.2% P123 maintained excellent catalytic activity and stability for 300 min at 700 °C, with CH₄ and CO₂ conversion of 75% and 78%, respectively. These findings provide valuable guidance for the rational design of efficient and stable Ni-based catalysts for DRM.

The development of low-cost and high-efficiency oxygen evolution reaction (OER) catalysts is essential to enhance the practicality of electrochemical water splitting for green hydrogen production. Layered double hydroxides (LDHs), especially those based on nickel and cobalt, have attracted attention due to their tunable composition, abundant redox-active sites, and earth-abundant constituents. However, their application is hindered by their limited conductivity and sluggish reaction kinetics. In this study, rare-earth-element-doped NiCo LDHs were synthesized directly on nickel foam through a one-step hydrothermal approach to improve the OER activity by modulating the electronic structure and optimizing the surface morphology. Among the representative catalysts, the incorporation of Sm significantly influenced the microstructure and electronic configuration of the catalyst, as confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Electrochemical tests showed that the optimized Sm-NiCo LDH achieved a low overpotential of 172 mV at 10 mA cm⁻² and a small Tafel slope of 84 mV dec⁻¹ in 1 M KOH, indicating an expanded electrochemically active surface and improved charge transport. Long-term stability tests further showed its durability. These findings suggest that Sm doping enhances the OER performance by increasing active site exposure and promoting efficient charge transfer, offering a promising strategy for designing rare-earth-modified, non-precious-metal-based OER catalysts.

Introduction: Hydrogen energy is a promising alternative to fossil fuels, yet its storage and transportation remain challenging due to flammability and low density. Liquid organic hydrogen carriers (LOHCs), such as bicyclohexane (BCH) derived from biphenyl (BP) hydrogenation, offer high hydrogen storage density and safety. This study investigates the impacts of support specific surface area (SSA) and preparation methods on the performance of Ru/SiO₂ catalysts in BP hydrogenation to BCH. Methods: Ru/SiO₂ catalysts with varying SSA were prepared using the strong electrostatic adsorption (SEA) and incipient wetness impregnation (IWI) methods with [Ru(NH₃)₆]Cl₃ as the precursor and fumed SiO₂ as the support. The catalysts were characterized using ICP-AES, XRD, N₂ physisorption, H₂-TPR, XPS, TEM, and HAADF-STEM. The catalytic performance was evaluated in a high-pressure autoclave under mild conditions (90 °C, 1.0 MPa H₂, 80 min) with product analysis conducted using GC-MS. Results: The 1.5 wt.% Ru/SiO₂-SEA (300) catalyst exhibited the best performance, achieving 99.9% BP conversion and BCH selectivity. This catalyst featured smaller Ru nanoparticles (average size 0.91 nm) and stronger metal-support interaction compared to the IWI-prepared catalysts. As the SSA of the SiO₂ support increased, the hydrogenation performance improved. Discussion: The research reveals that SiO₂ with high SSA can provide a greater number of active sites, thereby facilitating contact between reactants and the catalyst surface. This enhancement leads to improved catalytic activity and selectivity. Furthermore, the SEA method, which adjusts the solution pH, enables the uniform adsorption of metal ions onto the support surface through electrostatic interactions. This results in smaller Ru nanoparticle sizes and higher dispersion, significantly strengthening the metal-support interaction. Conclusion: The study highlighted the efficiency of the SEA method in developing the high-performance Ru/SiO₂ catalyst for BP hydrogenation. Higher SSA supports, particularly those prepared via SEA, yielded smaller Ru nanoparticles and enhanced dispersion, resulting in superior catalytic activity and selectivity. These findings offered some critical insights for advancing LOHC technology and hydrogen storage applications.

The esterification of terephthalic acid (PTA) with methanol to dimethyl terephthalate (DMT) was investigated using commercially available zeolite catalysts as the eco-friendly solid acids. Six typical zeolites (ZSM-5-25, ZSM-5-50, ZSM-5-100, ZSM-35, MOR, and β) were systematically evaluated. Among them, β zeolite showed excellent catalytic performance, achieving nearly 100% PTA conversion and 76.1% DMT selectivity under the conditions of 200 °C, of 0.5 MPa N₂ pressure, m(PTA):V(methanol) of 1:40 (g/mL), m(PTA):m(catalyst) of 10:1 over 4 h. The characterization results show that the catalytic efficiency was correlated with acid site strength, specific surface area, and mesoporous structure of the zeolite. After optimization, β zeolite achieved 100% PTA conversion and 94.1% DMT selectivity under the conditions of 200 °C, of 1 MPa N₂ pressure, m(PTA)/V(methanol) of 1:30 (g/mL), m(PTA)/m(catalyst) of 8:1 over 8 h. Moreover, β zeolite exhibited superior stability, maintaining over 92% of its initial activity after five cycles, highlighting its potential for sustainable DMT production.