Jul 2026· Journal of the American Chemical Society· Vol 148, pp. 31794-31805· 0 citations· 54 references
Medicine
Abstract
Solar-driven biomass valorization is pivotal for defossilizing the chemical industry. The oxidation of abundant, low-cost 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA)─a key monomer for next-generation bioplastics─is a long-sought goal yet hampered by sluggish kinetics, poor selectivity, and alkaline dependency. Here, spatially decoupled catalytic sites are engineered on two-dimensional carbon nitride (CN): covalently grafted cyanamide (CA) motifs at the edges and π-π stacked J-type nickel phthalocyanine (NiPc) dimers on the planes. This design features spatiotemporally cascaded charge transfer and dual-site catalysis, achieving 54- and 160-fold enhancements in the HMF conversion rate and H2 evolution rate, respectively, versus pristine CN, during HMF reforming in pure water. The FDCA production rate reaches 2.14 mmol g-1 h-1 with 98.2% selectivity, outperforming benchmark systems. Fundamentally, CA motifs steer an ultrafast hole-initiated selective HMF oxidation with a hole transfer rate of 2.4 × 1010 s-1 (an order of magnitude faster than CN). The resulting long-lived electrons are extracted by the bottom-layer NiPc and transferred via its single Ni atom to the top-layer single Ni atom for proton reduction, with an electron transfer rate of 7.4 × 104 s-1. The asymmetric charge kinetics suppresses charge recombination, yielding a charge transfer efficiency of 98.9%.
Polymorphism in covalent organic frameworks (COFs) offers a unique platform to decipher structure-property relationships, yet its impact on excited-state dynamics remains unexplored. Herein, we construct two chemically identical but topologically distinct 1D and 2D COF polymorphs to correlate framework architecture with photocatalytic performance. Impressively, in H2O2 photosynthesis coupled with furfuryl alcohol valorization, the 1D-TBPP-COF showed an exceptional H2O2 generation rate (18.75 mmol g-1 h-1) and selective oxidation of furfuryl alcohol to high-value 6-hydroxy-2H-pyran-3(6H)-one (PN) with PN formation rate of 28.14 mmol·g-1·h-1, substantially outperforming the 2D-TBPP-COF counterpart. Mechanistic investigations revealed that the intercalated dual-chain edges in 1D-TBPP-COF impose steric constraints on aromatic ring rotation, effectively suppressing vibrational relaxation losses and prolonging the charge-transfer state lifetime. In contrast, the conformationally flexible 2D-TBPP-COF permits greater rotational freedom, leading to non-radiative energy dissipation. This work establishes polymorphism engineering as a powerful strategy to manipulate excited-state dynamics in COFs for photocatalysis.
Fossil-derived diesel raises sustainability and air-quality concerns, motivating biomass-based alternatives; however, current biodiesel routes suffer from food-fuel competition, poor fuel properties, and energy-intensive upgrading. Electrocatalytic C─C coupling of biomass molecules followed by hydrodeoxygenation (HDO) offers a cleaner pathway, yet has been limited to dimer formation. Here, we successfully resolved this longstanding bottleneck through construction of Pd1Cu single-atom alloy electrocatalyst, a trimer of 5-hydroxymethylfurfural is obtained with 44.7% selectivity. The combined oligomer (dimer and trimer) selectivity reaches 95.0% with 93.2% Faradaic efficiency, production rate achieves a record high of ∼50 g gcat -1 h-1. Subsequent HDO converts the oligomers into heteroatom-free n-dodecane and n-octadecane diesel blendstocks. Operando spectroscopy reveals a surface-confined ketyl-radical pathway in which isolated Pd atoms regulate hydrogen-atom supply and substrate adsorption, favoring C─C coupling over hydrogenation. This work establishes an electricity-driven route for controlled carbon-chain growth from biomass platforms.
Shaowei Yang, Yingije Guo, Shixin Fa et al.· Angewandte Chemie· 0 citations
Covalent organic frameworks (COFs) have attracted considerable attention as promising photocatalysts for hydrogen peroxide (H2O2) production. To further improve their catalytic performance, a quaternary ammonium functionality was introduced into the bipyridine units of the COF via a post-synthetic modification strategy. Under identical irradiation conditions, the cationized Pry-COF-QA achieved a H2O2 production rate of 7.31 mmol·h–1·g–1, which is markedly higher than that of the non-protonated Pry-COF (5.50 mmol·h–1·g–1). To gain mechanistic insight into the enhanced activity, density functional theory (DFT) calculations were performed. The results indicate that the incorporation of the quaternary ammonium group fundamentally reconfigures the photophysical behavior. In addition to inducing a red shift in the absorption spectrum by narrowing the HOMO–LUMO energy gap, it more importantly converts the excitation character from a localized excitation (LE) state, which is unfavorable for charge separation, to an intramolecular charge transfer (ICT) state with well-separated spatial distribution. This efficient ICT pathway effectively suppresses electron–hole recombination, thereby significantly prolonging the lifetime of photogenerated charge carriers and ultimately facilitating efficient photocatalytic H2O2 production, while also providing a valuable guideline for the rational design of COF-based systems toward efficient photocatalytic H2O2 generation.
Zhihui Sun, Jiajia Li, Long-Yang Yang et al.· ACS Applied Energy Materials· 0 citations
The electrocatalytic co‐reduction of CO
2
and nitrate () to synthesize urea presents a sustainable alternative to traditional industrial processes, yet its efficiency is fundamentally limited by the kinetically mismatched activation and coupling of CO
2
and . To address this, we designed and synthesized two insoluble trinuclear ruthenium (Ru) cluster‐anchored polyoxometalate (POM) catalysts, Ru
3
SiW
12
and Ru
3
PW
12
, in which the central heteroatom of the Keggin‐type framework (Si vs. P) serves as a key structural variable. This work reveals that the central heteroatom critically modulates the synergy within the Ru‐cluster‐ligand ensemble, which in turn governs the catalytic interface. The optimized Ru
3
SiW
12
delivers a remarkable urea yield rate of 81.6 mmol h
−1
g
cat.
−1
with a Faradaic efficiency of 56.3% at −0.30 V versus RHE, substantially outperforming its P‐centered analog. In situ spectroscopic studies combined with electrochemical analysis demonstrate that the Si‐centered framework promotes a more effective activation of interfacial water, establishing an extensive hydrogen‐bonding network that facilitates proton transfer and hydrogenation of key C‐ and N‐intermediates, thereby boosting C–N coupling. This study highlights the pivotal role of engineering synergistic metal cluster‐ligand motifs via secondary coordination sphere tuning in insoluble matrices, offering a new design strategy for advanced electrocatalysts in sustainable chemical synthesis.
Photocatalytic biomass refining offers a promising strategy for the sustainable co-production of high-value chemicals and clean fuels. Herein, a coral-like bifunctional g-C3N4/Mn0.7Cd0.3S S-scheme heterojunction (CNMCS) was rationally constructed for simultaneous xylan photoreforming and hydrogen evolution. X-ray diffraction and transmission electron microscopy analyses confirm the formation of an interconnected hierarchical structure with intimate interfacial contact between g-C3N4 nanotubes and Mn0.7Cd0.3S nanoparticles, while x-ray photoelectron spectroscopy and density functional theory calculations reveal an S-scheme charge transfer pathway driven by the internal electric field. The optimized 6CNMCS photocatalyst achieves a glyceric acid yield of 77.6% and an H2 evolution rate of 2.89 mmol•gcat−1•h−1 without sacrificial agents. The enhanced performance is attributed to efficient charge separation and synergistic interfacial interactions that promote xylan adsorption and selective C–H bond activation. Mechanistic studies indicate that carbon-centered radicals and reactive oxygen species cooperatively drive selective C–C bond cleavage toward glyceric acid formation. This work provides a new strategy for integrating biomass valorization with clean hydrogen production.
Yulong An, Yuqi Liu, Qiaoge Lu et al.· Research· 0 citations
Dodecahydro-N-ethylcarbazole (12H-NEC) is a promising liquid organic hydrogen carrier (LOHC), yet its practical application is still constrained by slow dehydrogenation kinetics and extreme reliance on external heating even over most effective Pd-based catalysts. Here we identify that the hydrogen removal step with a high barrier is the precise kinetic bottleneck of 12H-NEC dehydrogenation, which remains underexplored. To effectively overcome this limitation, we report a light-activated dual-site hydrogen removal pathway using Pd nanoparticles supported on defective N-doped TiO2. Under irradiation, charge transfer from the support to Pd weakens Pd-H interactions, while accumulated holes on the support promote hydrogen spillover to Ti defect sites, generating weakened Ti-H species alongside Pd-H. This thereby initiates a new hydrogen formation dual-site pathway by combining Pd-H and Ti-H with an overall dehydrogenation barrier of 0.46 eV only, 0.74 eV lower than the conventional thermal Pd-localized pathway, resulting in a 42-fold higher H2 release rate relative to dark conditions at 140°C. Even under concentrated natural sunlight without external heating, near-complete dehydrogenation with a capacity of 5.65 wt.% H2 within 1 h is achieved from 12H-NEC. This work charts a promising course for practical hydrogen storage applications of LOHCs without secondary energy input.
Yu-Mo Li, Xiao-Yue Zhang, Chaoqun Li et al.· Angewandte Chemie· 0 citations