In this contribution, nanocatalysts with rather diverse architectures were designed to promote different intimacy degrees between Cu and SiO2 and consequently tune distinct Cu-SiO2 interactions. Previously synthesized copper nanoparticles were deposited onto SiO2 (NPCu/SiO2) in contrast to ordinarily prepared supported Cu/SiO2. NPCu@SiO2 and SiO2@Cu core-shell nanocatalysts were also synthesized, and they were all bulk and surface characterized by XRD, TGA, TEM/HRTEM, H2-TPR, XANES, and XPS. It was found that Cu0 is the main copper phase in NPCu/SiO2 while Cu2+ rules the ordinary Cu/SiO2 catalyst, and Cu0 and electron-deficient Cuδ+ species coexist in the core-shell nanocatalysts as a consequence of a deeper metal-support interaction. Catalytic performance could not be associated with the physical properties of the nanocatalysts derived from their architectures but was associated with the more refined chemical characteristics tuned by their design. Cu/SiO2 and NPCu/SiO2 catalysts led to the formation of furfuryl alcohol, evidencing that catalysts holding weak or no metal-support interaction have no significant impact on product distribution even in the aqueous phase. The establishment of such interactions through advanced catalyst architecture, allowing the formation of electron-deficient Cuδ+ moieties, particularly Cu2+ and Cu+ as unveiled by spectroscopic investigations, is critical to promoting the hydrogenation-ring rearrangement cascade mechanism leading to cycloketones.

Furfural-tolerant and hydrogen-producing microbial consortia were enriched from soil, with hydrogen production of 259.84 mL/g-xylose under 1 g/L furfural stress. The consortia could degrade 2.5 g/L furfural within 24 h in the xylose system, more efficient than in the sugar-free system. Despite degradation of furfural to furfuryl alcohol, the release of reactive oxygen species and lactate dehydrogenase was also detected, suggesting that furfuryl alcohol is also a potential inhibitor of hydrogen production. The butyrate/acetate ratio was observed to decrease with increasing furfural concentration, leading to decreased hydrogen production. Furthermore, microbial community analysis suggested that dominated Clostridium butyricum was responsible for furfural degradation, while Clostridium beijerinckii reduction led to hydrogen production decrease. Overall, the enriched consortia in this study could efficiently degrade furfural and produce hydrogen, providing new insights into hydrogen-producing microbial consortia with furfural tolerance.

The selective hydrogenation of the biomass platform molecule furfural (FAL) to produce furfuryl alcohol (FA) is of great significance to alleviate the energy crisis. Cu-based catalysts are the most commonly used catalysts, and their catalytic performance can be optimized by changing the preparation method. This paper emphasized the effect of calcination atmosphere on the performance of a Cu/Al2O3 catalyst for the selective hydrogenation of FAL. The precursor of the Cu/Al2O3 catalyst prepared by the ammonia evaporation method was treated with different calcination atmospheres (N2 and air). On the basis of the combined results from the characterizations using in situ XRD, TEM, N2O titration, H2-TPR and XPS, the Cu/Al2O3 catalyst calcined in the N2 atmosphere was more favorable for the dispersion and reduction of Cu species and the reduction process could produce more Cu+ and Cu0 species, which facilitated the selective hydrogenation of FAL to FA. The experimental results showed that the N2 calcination atmosphere improved the FAL conversion and FA selectivity, and the FAL conversion was further increased after reduction. Cu/Al2O3-N2-R exhibited the outstanding performance, with a high yield of 99.9% of FA after 2 h at 120 °C and an H2 pressure of 1 MPa. This work provides a simple, efficient and economic method to improve the C=O hydrogenation performance of Cu-based catalysts.

Photocatalysis is one of the most promising pathways to relieve the environmental contamination caused by the rapid development of modern technology. In this work, we demonstrate a green manufacturing process for the 3D/3D rod-shaped bamboo charcoal/Bi2WO6 photocatalyst (210BC-BWO) by controlled carbonization temperature. A series of morphology characterization and properties investigations (XRD, SEM, UV-vis DRS, transient photocurrent response, N2 absorption-desorption isotherms) indicate a 210BC-BWO photocatalyst with higher charge separation efficiency, larger surface area, and better adsorption capacity. The excellent photocatalytic performance was evaluated by degrading rhodamine B (RhB) (98.5%), tetracycline hydrochloride (TC-HCl) (77.1%), and H2 evolution (2833 μmol·g-1·h-1) coupled with furfuryl alcohol oxidation (3097 μmol·g-1·h-1) under visible light irradiation. In addition, the possible mechanisms for degradation of organic pollutants, H2 evolution, and furfuryl alcohol oxidation were schematically investigated, which make it possible to exert photocatalysis by increasing the active radical. This study shows that the combination of bamboo charcoal and bismuth tungstate can be a powerful photocatalyst that rationally combines H2 evolution coupled with furfuryl alcohol oxidation and degradation of pollutants.

Neo-formed contaminants (NFCs) are common in many foods, especially those subjected to high-temperature processing. Among these contaminants, products arising from the Maillard reaction, sugar reduction, thermal degradation of polyphenols and lipid oxidation, including acrylamide, furan, furfuryl alcohol, and hydroxymethylfurfural, are consistently linked to potential neoplastic effects. NFCs are found in globally traded commodities like coffee and cocoa, posing a significant risk due to their frequent consumption by consumers. A direct correlation exists between consumption frequency, exposure levels, and health risks. Hence, it\'s crucial to establish reliable methods to determine levels in both matrices, aiming to mitigate their formation and minimise risks to consumers. This review offers a comprehensive examination, discussion, and identification of emerging trends and opportunities to enhance existing methodologies for extracting and quantifying NFCs in coffee and cocoa. By presenting an in-depth analysis of performance parameters, we aim to guide the selection of optimal extraction techniques for quantifying individual NFCs. Based on the reviewed data, headspace extraction is recommended for furan, while solid and dispersive solid phase extractions are preferred for acrylamide when quantified using gas and liquid chromatography, respectively. However, it is worth noting that the reported linearity tests for certain methods did not confirm the absence of matrix effects unless developed through standard addition, leading to uncertainties in the reported values. There is a need for further research to verify method parameters, especially for determining NFCs like furfuryl alcohol. Additionally, optimising extraction and separation methods is essential to ensure complete compound depletion from samples. Ideally, developed methods should offer comprehensive NFC determination, reduce analysis time and solvent use, and adhere to validation parameters. This review discusses current methods for extracting and quantifying NFCs in coffee and cocoa, highlighting emerging trends and emphasising the need to improve existing techniques, especially for compounds like furfuryl alcohol.

The selective hydrogenation of furfural (FFA) to furfuryl alcohol (FA) is regarded as attractive transformation to achieve the sustainable synthesis of value-added chemicals from biomass resources. However, the conventional supported catalysts are significantly restricted by their narrow pore size, ununiform dispersion and easy leaching or aggregation of catalytic sites. Herein, we designed hollow UiO-66-NH2 as the support to encapsulate Pd nanoparticles (Pd@H-UiO-66-NH2) to achieve the highly active and selective conversion of FFA to FA. Benefiting from the void-confinement effect and substrate enrichment of hollow structure, as well as the surface wrinkles, the as-prepared catalyst Pd@H-UiO-66-NH2 exhibited 96.8 % conversion of FFA with satisfactory selectivity reaching up to 92.4 % at 80 °C, 0.5 MPa H2 in isopropanol solvent within 6 h. More importantly, as-prepared Pd@H-UiO-66-NH2 catalyst exhibited excellent long-term stability, as well as good universality toward a series of hydrogenation of unsaturated hydrocarbons.

Nb-based catalysts supported on porous silica with different textural properties have been synthesized, characterized, and tested in the one-pot reaction of furfural to obtain valuable chemicals. The catalytic results reveal that the presence of fluoride in the synthesis, which limits the growing of the porous silica, limits diffusional problems of the porous silica, obtaining higher conversion values at shorter reaction times. On the other hand, the incorporation of NbOx species in the porous silica provides Lewis acid sites and a small proportion of Brönsted acid sites, in such a way that the main products are alkyl furfuryl ethers, which can be used as fuel additives.

Furfural is a naturally occurring compound in bee honey, classified as a fermentation inhibitor. The aim of this study was to ascertain the concentration of furfural in mead worts, prepared at room temperature (unsaturated) and heated to boiling for 10 to 70 min (saturated), with an extract of 25 to 45°Brix. Moreover, the impact of the furfural on the fermentation course of mead wort was assessed. For this purpose, fermentation tests were conducted using mead wort (30°Brix) to which furfural was added at concentrations ranging from 1 to 100 mg/L. HS-SPME-GC-TOF-MS analysis revealed that the furfural concentration in mead worts varied between 2.3 and 5.3 mg/L. In saturated worts, the concentration increased by 2.8 to 4.5 times. Acidification of mead wort prior to boiling led to further increase in furfural concentration. The greatest changes occurred in the least concentrated worts, having the lowest buffer capacity. The addition of furfural to the mead wort did not inhibit fermentation, and an increase in attenuation was observed in the samples containing 2 mg/L of furfural compared to the control. Throughout the fermentation most of the furfural was reduced to furfuryl alcohol.

Furfuryl alcohol (FA) and other furanic compounds have garnered considerable attention in the quest for sustainable alternatives. FA-based resins have been used in various sectors that entail the release of FA into the environment. Hence, to ensure sustainability in this scenario, devising a dependable approach to its degradation is imperative. Given the crucial role of bacterial strains in the biodegradation of various organic pollutants, this study investigates the microbial degradation of FA, using bacterial strains isolated from sites that are constantly exposed to industrial waste. Three potential isolates were identified as B. paramycoides, B. cereus, and B. tequilensis by 16S rRNA gene sequencing. At a concentration of 300 µg/ml, these isolates demonstrated efficient FA degradation; 60-70% (at 300 µg/ml FA) and 50-60%, (at 500 µg/ml FA). Fourier-transform infrared (FTIR) spectroscopy and High-Performance Liquid Chromatography (HPLC) analysis further supported the result that the bacterial isolates consumed FA as the carbon source. Liquid chromatography-mass spectrometry (LC-MS) facilitates the detection of the major metabolic intermediate product in which FA gets transformed. The prominent peaks at 113 and 119 m/z obtained in the MS spectra of the degraded FA samples indicated the possibility of the conversion of FA into furoic acid or levulinic acid. The phytotoxicity bioassay findings revealed the non-toxic nature of the bio-transformed products as compared to pure FA. This investigation presents the initial documentation of the FA degradative potential of Bacillus strains, thereby augmenting the understanding of the prospective implementation of Bacillus species in industrial waste treatment projects.

Biscuit baking can cause the formation of heat-related toxic compounds, mainly through the Maillard reaction, including some volatile organic compounds (VOCs) that are potentially carcinogenic to humans. This study investigates the effects of different baking conditions and recipes on quality characteristics (moisture, water activity, colour, texture) and on the concentration of some VOCs (furfural, furfuryl acetate, 5-methylfurfural, furfuryl alcohol, 3-methylbutanal, hexanal) in biscuits. Specifically, lab-made biscuits baked under static and ventilated conditions and three commercial biscuit types categorised as shortbreads with eggs, with chocolate chips and dry petits were evaluated. Concerning the lab-made biscuits, the ventilated mode resulted in faster baking and a slightly lower concentration of investigated VOCs compared to the static mode. Besides the process conditions, the recipe also played a role in the final quality and target volatiles, whose concentrations were lower in dry petits than in shortbreads, which are characterised by higher sugar and fat contents.