SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3702-0
Construction of metal-mediated redox sites is an appealing approach to enhance photocatalytic CO2 reduction coupled with H2O oxidation. However, conventional static redox sites generally lack spatiotemporal matching during reaction processes due to the constraints of rigid structure and the linear scaling relationship of adsorbed species. Herein, an alkanolamine-Ir synergistic system was developed, where flexible monoethanolamine (MEA) molecules function as molecular ferries to selectively adsorb CO2 via carbamate formation, while adjacent Ir nanoparticles (NPs) serve as H spillover hubs that relay protons, creating spatiotemporal adaptability that synchronizes CO2 reduction and water oxidation. In addition, time-resolved in situ spectroscopy directly captures the rapid transformation of carbamate intermediates concurrent with sustained IrOOH intermediates formation. Microkinetic modeling further demonstrates that the MEA-Ir modified system (M-Ir/ACN) creates interconnected H spillover networks between Ir NPs and MEA, facilitating efficient proton transport that drives *COOH formation with a favorable thermodynamic energy. As a result, the M-Ir/ACN achieves a 20-fold increase in CO production compared to the pristine sample while maintaining high stability throughout 45 h of continuous operation. This study presents that flexible molecular ferries boost CO2 adsorption, and deciphers how flexible molecular-metal synergy directs the trafficking of CO2-derived intermediates toward highly efficient CO2 photoreduction.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3785-5
The effective separation and utilization of photo-generated carriers are critical for advancing photocatalysis, particularly in coupled reactions of H2 production and value-added chemical synthesis. Here, a sandwich-structured MnO2@ZnIn2S4@Ti3C2 hollow sphere was designed, with MnO2 and Ti3C2 loaded on the inner and outer surfaces of ZnIn2S4, respectively. MnO2 acts as an oxidation cocatalyst collecting photo-generated holes, while Ti3C2 serves as a reduction cocatalyst for electrons, promoting spatial separation of carriers and enabling spatially separated redox reactions. The hollow structure enhances light harvesting. The optimal catalyst achieves photocatalytic H2 production rate of 6.29 mmol g−1 h−1 and benzaldehyde production rate of 5.26 mmol g−1 h−1 from benzyl alcohol oxidation, significantly outperforming ZnIn2S4, MnO2@ZnIn2S4, and ZnIn2S4@Ti3C2. In situ irradiated X-ray photoelectron spectroscopy confirms effective carrier separation. In situ electron paramagnetic resonance and diffuse reflectance infrared Fourier transform spectroscopy reveal reaction intermediates. This work provides a strategy for designing efficient photocatalysts for coupled H2 production and selective oxidation.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.3724/2097-213X.2025.JFCT.0035
Iron-based catalysts in CO2/H2 atmospheres undergo dynamic carburization and oxidation phase transitions, complicating active-phase identification and stability control. This study prepared high-purity single-phase χ-Fe5C2 (Hägg carbide) and θ-Fe3C (cementite) via gas-solid carburization, with purity confirmed by XRD and Mössbauer spectroscopy. Fixed-bed reactor tests (H2/CO2 = 1, 0.1 MPa, 270–420 °C), pulse experiments (270 °C), and in situ XRD (10% CO2/He, 340 °C) were employed to investigate catalytic performance and structural evolution in the reverse water-gas shift (RWGS) reaction. Results show that χ-Fe5C2 exhibits higher RWGS activity but is more susceptible to oxidation, whereas θ-Fe3C demonstrates superior oxidation resistance but lower activity. Under RWGS conditions with H2, θ-Fe3C partially transforms into χ-Fe5C2; however, in 10% CO2 atmosphere, both carbides directly oxidize to Fe3O4 without inter-carbide transformation. In situ XRD at 340 °C and 0.1 MPa revealed that χ-Fe5C2 fully oxidizes within 11 h, while θ-Fe3C retains residual phase after 18.3 h, confirming its higher oxidation stability. These findings elucidate the atmosphere-dependent evolution mechanisms of χ-Fe5C2 and θ-Fe3C, providing experimental basis for phase-structure regulation and operational stability optimization in iron-based Fischer-Tropsch and RWGS catalysts.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(26)60657-3
Fe-Mn catalysts have attracted considerable attention for industrial Fischer-Tropsch synthesis (FTS) due to their ability to modulate product spectra. Carbon adsorption and permeation on catalyst surfaces are critical elementary steps in the in situ formation of active iron carbide phases. Here, density functional theory (DFT) calculations systematically investigate the atomistic structures, thermodynamic stabilities, and electronic properties of carbon-deposited Fe-Mn alloy surfaces at the early stage of carburization. These surfaces exhibit distinct thermodynamic sensitivity to carbon atoms adsorbed on the surface and permeating into interstitial sites. By combining DFT with minima-hopping structural searches, we demonstrate that the initial stage of carbon permeation cannot trigger surface reconstruction to form iron carbide phases. The addition of manganese thermodynamically hinders carbon permeation. Although deposited carbon atoms modulate the electronic structure of metals, manganese retards the shift of d-band centers toward those of bulk iron carbide phases. This study provides atomic-scale insight into the in situ evolution of Fe-Mn catalyst surfaces during carbon deposition, indicating that manganese promoter has a noticeable effect on carbon permeation.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4282-y
Recovering gold from electronic waste (e-waste) is critical for sustainable resource management, yet conventional adsorbents suffer from poor acid stability and slow kinetics. Here, we report an acid-resistant cationic covalent organic framework (COF), TAPT-TNV, synthesized via irreversible Zincke reaction. TAPT-TNV exhibits exceptional stability in concentrated acids, retaining crystallinity and porosity after exposure to 12 M HCl and 6 M HNO3. The cationic skeleton, balanced by Cl− counterions, enables rapid and selective capture of AuCl4− through anion exchange, complemented by chemical reduction at triazine units. Adsorption kinetics are fast, reaching equilibrium within 30 minutes, with a maximum capacity of 1835.5 mg g−1 at pH 1. In real e-waste leachate, TAPT-TNV achieves a gold recovery rate of 99.42%, demonstrating high selectivity over competing metal ions. This work introduces a robust COF platform for precious metal recovery, addressing the limitations of hydrolytically unstable frameworks.