The fractionation of lignocellulosic biomass via pretreatment is a critical step for its valorization. However, the efficiency of pretreatment is often limited by the robust lignin-carbohydrate complex (LCC) structure. This study employed the cooking with activated oxygen and solid-alkali (CAOSA) pretreatment, using H2O2 and O2 as the dual oxidant sources, to pretreat various types of woody biomass. The CAOSA pretreatment with H2O2 and O2 achieved over 90% removal of hemicellulose and lignin, and over 90% retention of cellulose. In addition, the enzymatic hydrolysis efficiency of various cellulose pulps was obtained around 90% after the CAOSA pretreatment. Notably, the hemicellulose was degraded into organic acids like formic acid during the CAOSA pretreatment with H2O2 and O2, which could be served as an in-situ hydrogen source for the hydrodeoxygenation reaction of the lignin dissolved in the cooking liquor, directly producing lignin monophenols with a yield close to the theoretical yield (based on β-O-4 linkage). Mechanism studies revealed that introducing H2O2 as an oxidation additive to CAOSA pretreatment promoted the generation of reactive oxygen species (ROS), thereby enhancing the cleavage of glycosidic and C-C bonds in hemicellulose, resulting in more hemicellulose degradation into small-molecular-weight acids. It also promoted cleavage of β-O-4 and C-C bonds in lignin. In-situ generated small-molecular-weight acids from hemicellulose suppressed the cleavage of lignin aromatic structures, thereby improving lignin recovery with a high delignification rate. This study provides theoretical guidance and technical support for efficient alkali-oxygen pretreatment and comprehensive utilization of woody biomass.

Reductive amination of biomass-derived levulinic acid (LA) to N-substituted-5-methyl-2-pyrrolidone (BMP), versatile nitrogen-containing chemicals, under ambient conditions is highly desirable but challenging due to inefficient H2 activation. To address this limitation, a platinum (Pt)-based catalyst supported on oxygen-vacancy-rich CeO2 (Pt/CeO2-Vo) was developed, comprising uniformly dispersed Pt/PtO2 heterostructures with adjacent Pt–O–Ce interfacial sites. At these Pt–O–Ce interfaces, electron-deficient Pt and electron-rich O atoms, modulated by neighboring oxygen vacancies, facilitate in situ hydrogen spillover from Pt nanoparticles, generating highly reactive Hδ⁺–O···Pt–Hδ– pairs that enable the efficient hydrogenation of the condensation intermediates formed between LA and amine substrates. Therefore, Pt/CeO2-Vo achieved a high BMP yield of 95.2% with a productivity of 476.0 mol/(mol·h) within 1 h under ambient conditions. Even at a high LA concentration of 11.4% (w), the yield remained above 90%, demonstrating the catalyst’s efficiency under ambient conditions. It also showed excellent recyclability over six consecutive cycles and maintained stable performance for over 80 h in a fixed-bed flow reactor. This work underscores the critical importance of interfacial engineering in optimizing Pt-based catalysts and provides a robust and sustainable strategy for biomass upgrading under mild conditions.

The reductive amination of furfural (FUR) to furfurylamine (FAM) is one of the key reactions for the sustainable production of value-added primary amines in biomass valorization. Herein, we have constructed a series of Ndoped porous carbon confined Co nanoparticles (CoNC) based on the pyrolysis of Co-containing ZIF-67 at different temperatures for the synthesis of FAM from FUR. The reductive amination activity of as-obtained CoNC catalysts shows a volcano plot as the pyrolysis temperature increases. The optimal CoNC-750, obtained by pyrolysis at 750 degrees C, could afford a maximum FAM yield up to 99 % at 110 degrees C, 0.3 MPa of NH3, 2 MPa of H2 in methanol, reflecting one of the excellent performances in terms of FAM yields for Co-based catalysts. Besides, no apparent deactivation of the CoNC-750 is observed after six consecutive runs, indicating an excellent stability. Through a combination of advanced characterizations, a positive linear relationship between the densities of the strong acid sites and the corresponding FAM productivities of CoNC catalysts has been revealed, indicating that the strong acid density is a key descriptor for facilitating the FUR-to-FAM transformation. This study provides an efficient approach for fabricating high-performing non-noble metal catalysts for the reductive amination of biomass-derived platform molecules, which could be of great aid for green and sustainable production of primary amines and beyond.

The accumulation of heavy metals restricts the safe agricultural utilization of pig manure. Co-pyrolysis with organic additives offers a promising strategy to overcome the physicochemical defects of manure-derived biochar and enhance metal sequestration. This study investigated the co-pyrolysis of pig manure with distinct solid wastes including food residue, tea stems, and spent coffee grounds at 450-750 °C to elucidate heavy metal transformation mechanisms. Results demonstrated highly efficient immobilization for Cu, Cr, and Ni; specifically, in the tea stem co-pyrolysis biochar at 750 °C, the residual fractions of Cr and Ni reached 87.15% and 80.55%, respectively. Supported by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, this stabilization is driven by a dual pathway: direct precipitation into stable mineral phases such as Cu5FeS4 and MgCrO4, and surface complexation via persistent Si-O and C-O functional groups within the aromatized carbon network. Principal Component Analysis (PCA) confirmed that carbon skeleton aromatization and matrix alkalinity dictate the conversion of bioavailable fractions into inert residual forms. Conversely, Zn stabilization exhibited high temperature sensitivity, requiring over 650 °C for extensive mineralization. Furthermore, feedstock composition critically regulated metal fate: chloride-abundant food residue hindered Zn and Mn solidification by forming soluble chloro-complexes, whereas lignin-rich matrices significantly promoted biochar aromatization and porosity, reinforcing metal sequestration via enhanced cation-π interactions. Finally, comprehensive environmental risk evaluations revealed an asymmetrical characteristic of high total accumulation versus low ecotoxicity. Lignin-assisted high-temperature treatments effectively suppressed the ecological risk indices of the target metals, validating co-pyrolysis as a robust thermochemical strategy for the safe remediation and resource recovery of hazardous livestock waste.

The selective aqueous-phase conversion of concentrated, bio-based 5-hydroxymethylfurfural (HMF) toward 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) represents a key step in sustainable chemical synthesis. Despite its significance, the reaction is frequently limited by inefficient H2 activation and non-selective activation of HMF. Herein, we report a Pd-based catalyst anchored on oxygen-vacancy-rich Ni1Co2Ox-VC (Pd/Ni1Co2Ox-VC) that achieves outstanding BHMTHF yields of 83.1-93.8% even at high HMF concentrations (up to 45 wt%) and low temperatures (30-60 degrees C). The remarkable performance is attributed to an efficient relay hydrogenation mechanism, wherein H2 is heterolytically cleaved into polarized hydrogen species at the Pd/PdO heterointerface with interfacial Pd-O-Co sites. Furthermore, the incorporation of NiO selectively enhances furan ring adsorption while suppressing undesirable side reactions. The catalyst also demonstrates excellent stability over 100 h of continuous operation at 10 wt% HMF, underscoring its industrial relevance. This study paves the way for efficient high-conversion hydrogenation of biomass-derived platform molecules under industrially viable conditions.

We have developed a highly efficient and stable non-noble metal-based heterogeneous catalyst for the selective oxidation of HMF to DFF. Mixed oxide catalysts with different Mn/Ni molar ratios were synthesized using the urea precipitation method. The Mn6.6NiOX catalyst exhibited a 95.33% HMF conversion rate and a 99.39% DFF selectivity under the conditions of 110 degrees C, 2 h, 1 MPa O-2, and N,N-dimethylformamide. Experimental results indicate that the introduction of NiO can effectively regulate the crystal structure of MnO2, forming an amorphous Mn & horbar;O & horbar;Ni interface, which significantly increases the specific surface area (SSA) of the catalyst while reducing the binding energy of surface lattice oxygen (O-L), promoting the generation of oxygen vacancies (O-V), and thereby enhancing the adsorption and activation capabilities of O-2. Combined adsorption experiments and kinetic analysis revealed that Ni species preferentially anchor the hydroxymethyl group in HMF molecules, enhancing reaction selectivity. Further experiments demonstrated that the Mn6.6NiOx catalyst, under certain conditions, could achieve an HMF conversion rate of 87.52% and a DFF selectivity of 85.81% even at a high substrate concentration of 10 wt% HMF.

The lack of catalysts with excellent intrinsic activity and durability has hindered the application of electrooxidation for biomass-derived molecules with abundant functional groups. Taking 5-hydroxymethylfurfural (HMF) as an example, the HMF electrooxidation (HMFOR) process consists of the 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) and the 2,5-furandicarbaldehyde (DFF) routes, which involve oxidation of aldehydes/hydroxymethyl groups that cannot be regulated by catalyst design strategies. Herein, we report rapidly constructed bifunctional Ru-NiMn/NF-IH catalysts using induction heating and reveal the intrinsic connection between HMFOR and hydrogen evolution reaction (HER) with the catalytic interface. Atomic-level Ru promoted the Niδ+ species (δ ≥ 3) formation by facilitating deprotonation, which facilitates the cleavage of the C–H bond. The Ru-Mn site precisely regulates HMFOR from preferential hydroxymethyl oxidation to preferential aldehyde. The HER//HMFOR process catalyzed by Ru-NiMn/NF-IH can be carried out at industrial current densities (∼1,000 mA/cm2 at 1.50 V for 200 mM) in a flowing system. Technical-economic analysis has confirmed the economic viability of this system.

Selective hydrogenation of furfural (FFL) to furfuryl alcohol (FAL) represents a pivotal paradigm in sustainable biomass valorization. In this work, nanoscale Cu clusters were encapsulated in silicalite-1 (S-1) zeolite using in-situ synthesis, and further modified by a rare-earth element of La for regulating the catalyst microenvironment. The obtained La-Cu@S-1 can provide an enhanced performance in the FFL-to-FAL transformations, with 98.6% conversion of FFL and 99% selectivity of FAL at 110 °C, 20 bar H2, and 3 h. Besides, La-Cu@S-1 shows a good stability without apparent catalyst deactivation upon four consecutive runs. Extensive characterization research reveals that La addition could provide anchoring sites for Cu nanoclusters via an enhanced electronic interaction, thereby effectively suppressing metal leaching and agglomeration during the liquid-phase catalysis. Additionally, La addition could modulate the zeolite microenvironment of encapsulated Cu nanoparticles and notably stabilize the conventionally unstable Cu+ species at a high proportion, even in a reductive H2 atmosphere during catalysis, accounting for the enhanced activity and stability. This study showcases La modification as an efficient approach to rationally develop metal-zeolite combinations with enhanced performance, promoting potential utilization and development of rare-earth elements in the valorization of biomass and other renewable energy.

Ricinoleic acid, an industrially high-value hydroxy fatty acid traditionally sourced from castor seed oil. However, plant-based production is plagued by challenges such as inherent toxicity, environmental risks, and unstable supply. Microbial biosynthesis provides a safer and more sustainable alternative, eliminating the need for land cultivation, shortens production cycles, and mitigates the toxicity risks associated with castor seed harvesting. Furthermore, microbial production of ricinoleic acid in the form of single cell oil (SCO) confers significant advantages over free fatty acid, including enhanced stability and reduced cytotoxicity. In this study, the oleaginous yeast Yarrowia lipolytica was metabolically rewired via a multi-pronged strategy: boosting the synthesis of oleoyl-CoA (the precursor of ricinoleic acid), mimicking plant acyl editing to refine phosphatidylcholine pool precursors, promoting the assembly of ricinoleic acid into storage triacylglycerols, and suppressing competing degradation pathways. Employing this integrated engineering approach, the final engineered strain YY-20 accumulated 729.4 mg/L of ricinoleic acid in shake flask cultures, accounting for 28.3% of total fatty acids. More notably, fed-batch fermentation in a bioreactor achieved a record-high ricinoleic acid titer of 6.0 g/L (comprising 26.1% of total fatty acids), accompanied by 22.8 g/L of SCO and a lipid content of 37.3% dry cell weight. These results demonstrate the efficacy of coordinated lipid pathway engineering in establishing Y. lipolytica as a robust microbial cell factory for hydroxy fatty acid production. The high SCO titer and efficient ricinoleic acid synthesis underscore the potential of this platform for the scalable industrial biomanufacturing of ricinoleic acid and other high-value unusual fatty acids.

Rare sugars are monosaccharides and their derivatives that occur only in trace amounts in nature. Owing to their low caloric value and diverse physiological activities, they have attracted increasing attention as functional ingredients in the food, pharmaceutical, and health-related industries. However, their limited natural abundance and the inefficiency of traditional production methods remain significant challenges for large-scale application. Biosynthesis has emerged as a promising platform for rare sugar production due to its mild reaction conditions, environmental compatibility, and high catalytic specificity. With advances in synthetic biology and metabolic engineering, multiple biosynthetic routes have been developed. Further improvements in productivity and industrial feasibility increasingly depend on the coordinated integration of multi-level engineering strategies. In this review, we first briefly introduce the physiological functions and applications of representative rare sugars, including D-allulose, D-tagatose, D-allose, L-ribose, L-ribulose, and L-xylulose. We then provide a systematic overview of recent advances in biosynthesis, with a focus on metabolic engineering, enzyme engineering, biocatalysis, and fermentation process optimization. Finally, we discuss the key challenges and future directions for developing efficient microbial cell factories for rare sugar production.

The catalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is an important reaction in the sustainable production of polymers from biomass resources. To advance the environmental sustainability of this process, it is crucial to develop a catalytic system that circumvents the need for liquid alkaline media, which have been conventionally employed in HMF-to-FDCA conversion. Herein, we developed an efficient catalytic system comprising Ru nanoparticles supported on Na-type zeolite Y (Ru/Na-Y) for the base-free oxidation of HMF to FDCA. Reducing the particle size of Ru significantly enhances the activity of the Ru/Na-Y catalysts. Specifically, the optimized Ru/Na-Y-300N-200H, featuring Ru nanoparticles with an average size of similar to 2.5 nm, afforded nearly 100 % HMF conversion and similar to 85 % FDCA yield under base-free aqueous-phase conditions at 100 degrees C and 5 MPa air pressure. Kinetic studies further evidenced that Ru/Na-Y-300N-200H could effectively catalyze the sequential oxidation of both alcohol and aldehyde groups during the HMF-to-FDCA conversion. Comprehensive characterizations and DFT calculations elucidated the enhanced interaction between Ru centers and Na sites in the Ru/Na-Y-300N-200H due to the smallest Ru particle size. The unique Ru-Na synergistic effect was thus realized, which could facilitate the activation of O-2 and the generation of O-2(center dot-) radicals as active oxygen species, while simultaneously boosting the rate-determining step of 5-formyl-2-furancarboxylic acid (FFCA) oxidation to FDCA, resulting in a high FDCA yield. These findings unveil promising prospects for developing advanced metal-zeolite bifunctional catalysts, which could facilitate the base-free oxidation of biomass-derived HMF into FDCA.

Zeolites are crystalline microporous materials extensively applied in ion exchange, adsorption, separation, and catalysis. However, small-, medium-, and large-pore zeolites with 8-12-membered-ring (MR) frameworks suffer from intrinsic diffusion and reactivity limitations in the conversion of bulky molecules. Recent advances in molecular engineering have enabled the synthesis of extra-large-pore (ELP) frameworks with window sizes exceeding 12-MRs, which bridge the gap between microporous and mesoporous materials. These architecturally unique ELP zeolites facilitate the diffusion of bulky molecules, unlocking opportunities in catalysis, separation, and environmental remediation. This review consolidates the rapidly expanding field of ELP zeolites, providing a comprehensive overview ranging from early germanosilicate and phosphate-based systems to recent high-silica and aluminosilicate ELP frameworks with three-dimensional interconnected pore networks. First, we delineate the structural characteristics of ELP zeolites (ring aperture, framework density, and pore dimensionality) and discuss advanced characterisation techniques that have enabled their precise structural elucidation. We then systematically summarise the synthetic methodologies, encompassing the prevailing 'bottom-up' and 'top-down' strategies, as well as emerging approaches such as high-throughput screening and machine learning-guided framework design. Representative ELP zeolites across phosphate-, germanosilicate-, pure-silica, aluminosilicate-, and heteroatom-containing frameworks are examined with respect to their functional potential in adsorption, separation, and catalysis. Finally, key challenges, including the high cost of multi-step templating, reliance on germanium, structural framework defects, and environmentally unsustainable synthesis methods, are highlighted, along with perspectives on accelerating the development of next-generation ELP zeolites through data-driven design integrated with in situ characterisation.

1,6-Hexanediol (1,6-HDO) can be synthesized via aqueous-phase hydrogenation of dimethyl adipate (DMA). However, this process requires high temperatures (>200 °C) over Ru catalysts and suffers from low selectivity when reaching high low-temperature activity. In this study, highly selective RuSn/SiO2 catalysts were developed for the DMA-to-1,6-HDO transformation. The Sn addition demonstrated a promotion effect on the selectivity of 1,6-HDO due to the inhibition of the undesired hydrogenolysis of C-C and C-O bonds. The optimized 4Ru2Sn/SiO2 catalyst afforded a high 1,6-HDO selectivity of ~98.4% at ~100% DMA conversion, almost double the value obtained over 4Ru/SiO2 in H2O under 120 °C and 8MPa H2. Additionally, the 4Ru2Sn/SiO2 catalyst can be reusable up to five recycling cycles with almost unchanged activity and selectivity. Sn was found to be in close contact with the Ru centers in the form of SnOx, which reduces the proportion of Ru0 species in RuSn/SiO2, thereby significantly suppressing hydrogenolysis side reactions and enabling high selectivity toward 1,6-HDO in the aqueous phase. The present results clearly indicate the beneficial effect of Sn on enhancing 1,6-HDO selectivity in Ru-based catalysts during the low-temperature hydrogenation of DMA in aqueous medium, suggesting potential applicability to a wide range of ester compounds.

Wood, as a natural and renewable resource, possesses a unique hierarchical porous structure and chemical components consisting of cellulose, hemicellulose, and lignin. Through physical, chemical, or biological methods such as lignin removal, component separation, or in-situ modification of wood, it can be transformed into advanced material platforms with multi-scale structural design. This article systematically reviews the preparation strategies, performance characteristics, and application progress of wood-based hydrogels. By using two main technical paths of "top-down" lignin removal to retain the natural framework and "bottom-up" component separation and reconstruction, wood-based hydrogels with excellent mechanical properties and tunable functions have been successfully developed. These materials show great potential in flexible sensing, biomedical, and energy storage fields. The introduction of artificial intelligence technologies, such as machine learning, is promoting the transformation of material research from empirical trial-and-error to data-driven rational design. However, this field still faces challenges such as the difficulty in balancing component separation efficiency and scale-up costs, and the unclear relationship between complex structures and their macroscopic properties. Future research should focus on green and efficient component separation technologies, deepening the understanding of multi-scale structure-performance relationships, and actively expanding their applications in emerging fields such as wearable sensors and sustainable flexible electronics.

The selective hydrogenation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) under mild conditions holds great significance for sustainable chemical production. However, this process remains hindered by challenges such as the instability of HMF in aqueous media and the insufficient efficiency of H2 activation. Herein, a Pd catalyst supported on oxygen-vacancy-enriched MnOx-VC (Pd/MnOx-VC) is developed, featuring highly dispersed Pd/PdO heterostructures with abundant Pd-O-Mn interfacial active sites. Notably, Pd/MnOx-VC offered a high BHMTHF formation rates of 366.5 molBHMTHF center dot molPd- 1 center dot h- 1 in water under mild conditions. Moreover, the catalyst was able to efficiently convert both purified and crude HMF at high concentrations (>= 10 wt%), achieving BHMTHF yields exceeding 90 % in either batch or continuous-flow reactor under low temperatures (30-60 degrees C), underscoring its potential for industrial application. Mechanistic studies revealed that the relay activation of H2 over Pd nanoparticles and adjacent Pd-O-Mn sites generates polarized H delta+-H delta- pairs, which primarily contributed to the outstanding activity of Pd/MnOx-VC. This work highlights the importance of interfacial site engineering in designing highperformance catalysts for HMF hydrogenation.

Aryl migration represents a powerful strategy for the selective reconstruction of carbon skeletons with high atom- and step-economy. Herein, an efficient cobalt-catalyzed 1,2-aryl migration for the intramolecular hydroarylation of allylic alcohols via hydrogen atom transfer (HAT) is presented. With oxygen as the oxidant and HFIP as the solvent, this protocol proceeds efficiently and features good functional group tolerance, offering a powerful approach to synthesize functionally diverse alpha-aryl ketones in moderate to good yields with excellent chemoselectivity. Preliminary mechanistic studies reveal a metal-hydride hydrogen atom transfer (MHAT) pathway, followed by radical-polar crossover (RPC) and 1,2-aryl migration.