ACS Catalysis 最新文献

Controlling the dynamic mobility of catalyst surface active sites and their interactions with the surrounding environment is critical in generating active surfaces that directly influence catalytic activity and selectivity. Here, we report a strategy for tailoring the dispersion and electronic environment of single-atom Rh catalysts by decorating the alumina support with highly dispersed (HD) cerium and molybdenum oxides. The resulting catalysts exhibit markedly different behaviors in the Reverse Water–Gas Shift (RWGS) reaction. In particular, Rh/MoO_x(HD)/Al₂O₃ maintains atomically dispersed Rh even at elevated temperatures (up to 400 °C), achieving CO selectivity of up to 100% and resisting sintering via the formation of a newly developed structure featuring Rh single atoms embedded in MoO_x clusters. In situ spectroscopy and microscopy analyses confirm the stabilization of Rh and the dynamic evolution of the Rh–Mo coordination under the reaction conditions. Our findings highlight the power of support modification in steering active site structure and activity, offering a pathway toward enhanced performance and tunable single-atom catalysts for CO₂ valorization.

Electrooxidation reaction of ethylene glycol (EG) offers an efficient route for producing value-added chemicals (glycolic acid (GA)) and facilitates coupled hydrogen (H₂) production. However, its practical performance is often hindered by sluggish reaction kinetics and catalyst deactivation, both of which are strongly influenced by interfacial microenvironments. Here, we report an interfacial engineering strategy that employs polydopamine (PDA) to modulate the hydrogen-bonding network at the Au catalyst-electrolyte interface, which mitigates the oxidative deactivation of Au, achieving a 1.78-fold enhancement for electrooxidation of EG-to-GA compared with the pure Au catalyst (0.41 vs 0.23 mmol cm^–2 h^–1 at 1.5 V vs RHE). Mechanistic studies reveal that Au sites generate reactive OH* species to drive EG oxidation, and the PDA layer enriches EG near active sites. Moreover, PDA can regulate the interfacial hydrogen-bonding network, that is, generating strong hydrogen bonding with EG disrupts the tetrahedral water network, generating a more open and dynamic hydration environment that facilitates EG adsorption and activation. When integrated into a flow-cell electrolyzer, Au/PDA catalyst delivers efficient coproduction of glycolic acid (3.0 mmol h^–1) and hydrogen (8.1 mmol h^–1) with high selectivity under a 0.8 V operating voltage. This work elucidates a molecular-level mechanism for hydrogen-bond-mediated interfacial regulation and establishes a general design principle for enhancing alcohol electrooxidation through adaptive hydrogen-bonding engineering.

Engineered luciferases have transformed biological imaging and sensing, yet optimizing NanoLuc luciferase (NLuc) remains challenging due to the inherent stability-activity trade-off and its limited sequence homology with characterized proteins. We report a hybrid approach that synergistically integrates deep learning with structure-guided rational design to develop enhanced NLuc variants that improve thermostability and thereby activity at elevated temperatures. By systematically analyzing libraries of engineered variants, we established that modifications to termini and loops distal from the catalytic center, combined with preservation of allosterically coupled networks, effectively increase thermal resilience while maintaining enzymatic function. Our optimized variants─notably B.07 and B.09─exhibit substantial thermostability enhancements (increased melting temperatures of 7.2 and 5.1 °C, respectively), leading to the sustained activity of a high-activity mutant at elevated temperatures. Molecular dynamics simulations and protein folding studies elucidate how these mutations favorably modulate conformational landscapes without perturbing the substrate binding architecture. Beyond providing a thermostabilized tool for bioluminescence applications, our integrated methodology presents a framework for engineering enzymes when traditional homology-based approaches fail and stability-activity constraints present formidable barriers to improvement.

Subsurface hydrogen transport in alloys offers poison resistance and enhanced adsorption capacity compared to surface-mediated processes, yet its underlying dynamic mechanisms remain largely elusive. Herein, we employ machine learning-accelerated molecular dynamics simulations to investigate atomic-scale hydrogen spillover dynamics in Pt₁/Ag single-atom near-surface alloys. We identify two distinct penetration pathways: a H–H collision-induced mechanism, where impulsive interactions between dissociated H atoms at the Pt₁ site transiently enhance the vertical kinetic energy of one atom, enabling barrier overcoming and subsurface entry; and a surface spillover-mediated mechanism, involving initial hopping of hydrogen species across Ag sites coupled with stabilization from subsurface Pt atoms that collectively facilitate subsequent penetration. In addition, subsurface diffusion shows higher mobility and a stronger temperature response than surface diffusion. These findings provide fundamental insights into subsurface hydrogen transport and establish design principles for advanced catalytic and hydrogen storage systems through subsurface engineering.

The development of highly efficient nanocatalysts toward low-temperature glucose hydrogenation is still challenging but extremely desirable for underutilized biomass upgrading. Here, we develop LN_1–xC_xO-R catalysts, comprising NiCo nanoalloys supported on defective La₂O₃, derived from the controlled reduction of LaNi_1–xCo_xO₃ perovskites. Combined experimental studies and density functional theory calculations reveal interfacial charge transfer between the NiCo alloy and La₂O₃. The resulting electron-deficient NiCo sites favor the facile dissociation of H₂, while the electron-rich La₂O₃ support, enriched with oxygen vacancies, facilitates glucose adsorption and activation–collectively accelerating its conversion to sorbitol. Among the series, LN_0.8C_0.2O-R enables the efficient low-temperature hydrogenation of biomass-derived sugars, achieving a sorbitol productivity of 4.31 g_Sor g_Cat^–1 h^–1 and selectivity of 97.9% at 80 °C. This interfacial synergistic approach offers valuable insights for the rational design of high-performance heterojunction catalysts for low-temperature biomass conversion.

Conformationally defined [n]metacyclophanes represent promising targets in drug discovery and materials science. However, the catalytic asymmetric syntheses of these atropisomers is challenging because of their conformational lability and high degrees of ring strain. This paper presents an ansa chain editing strategy for the atropo- and enantioselective synthesis of planar-chiral [n]metacyclophanes. This approach involves chiral phosphoric acid-catalyzed desymmetrization or (dynamic) kinetic resolution, affording [9]–[14]metacyclophanes in high yields and enantioselectivities. Racemization kinetic studies reveal that the conformational stability is governed by the ansa chain length, the size of the benzene ring substituent, and the atropisomerism of the tertiary amide. Computational studies indicate that C–H···O interactions and catalyst distortion in the transition states are key determinants of the absolute configuration in the final product. Furthermore, biological evaluations reveal promising anti-inflammatory activities for these macrocycles, which are attributed to the rebalancing of inflammatory homeostasis in macrophages within a lipopolysaccharide-induced model.

Photocatalytic H₂O₂ synthesis presents a promising alternative to the energy-intensive anthraquinone process. However, carbon nitride-based photocatalysts suffer from limited H₂O₂ production due to weak O₂ binding and inefficient formation of *OOH intermediates at the active sites. Here, we demonstrate that engineering coordination-deficient Ni sites in carbon nitride significantly enhances photocatalytic H₂O₂ production through the systematic reduction of Ni coordination from fully coordinated Ni–N4 to coordination-deficient Ni–N2. Density functional theory calculations reveal that the coordination-deficient Ni–N2 sites exhibit upshifted d-orbital centers and strengthened Ni 3d–O 2p orbital coupling. This electronic modification transforms O₂ adsorption from Pauling-type to Griffiths-type configuration, facilitating *OOH intermediate stabilization. Guided by these insights, we synthesized a series of Ni sites with a tunable coordination deficiency through an intercalation–exfoliation strategy. The optimal Ni–N2 catalyst achieves a H₂O₂ production rate of 240.23 μmol g^–1 h^–1, representing a 6.07-fold enhancement over pristine carbon nitride, with 94.15% H₂O₂ retention efficiency. Femtosecond transient absorption spectroscopy reveals ultrafast electron injection into Ni d-orbital trap states on the picosecond time scale, creating long-lived excited states essential for O₂ activation. In situ spectroscopic studies confirm the preferential *OOH formation on the Ni–N2 sites, validating the direct two-electron pathway.

Highly robust Ir complexes were developed for the additive-free dehydrogenation of formic acid (FA) in water under harsh reaction conditions. Phenanthroline as the core unit of the ligand with amino groups as substituents enhanced both catalytic activity and durability with a negligible amount of CO formed as a contaminant (below 0.5 ppm). Notably, when a 20 M FA solution was continuously supplied to the Ir phenanthroline complex with two pyrrolidino-substituents (0.2 μmol) in 8 M FA (100 mL) under reflux conditions, a maximum turnover frequency of 245,000 h^–1 was maintained for 14 h, and a turnover number of up to 14 million was achieved. Additionally, the iridium-bound formato intermediate was characterized in situ using ¹H and ¹³C NMR, as well as electrospray ionization-mass spectrometry.