C4 Alcohols Research Articles

Liquid–Gas Phase Transition Actuator: Rejuvenation Procedure Extended and Open-Air Performance

To achieve the actuation of silicone-based foamed composites, a liquid–gas phase transition of the liquid captured in its pores is employed. The uncertainty of key parameters for a single or sequential open-air performance of such soft actuators limits their application. To define the main characteristics of the composites, in this work, two functions of the liquid there were separated: the pore-forming agent (FPA) and working liquid (WL). It was demonstrated that the composites can be fabricated using either ethanol or methanol as the PFA, while any of the C1-C4 alcohols can be used as the WL. The results of the sequential actuation tests of the composites revealed that pore formation depends on the composite viscosity during curation, while their expansion in single heat experiments can be approximated by a unified linear relation. Based on a Mendeleev–Clapeyron equation, the qualitative model for predicting the actuator strain is proposed. It was found that the composites with C3–C4 alcohols as the WL outperform ethanol-containing composites on the number of cycles survived under open-air conditions. These findings pave the way to control the operation of soft actuators by manipulating WL variation and PFA content during the composite cure to set the operation temperature and degree of expansion of pre-formed actuators.

Rational design and characterization of enhanced alcohol-inducible synthetic promoters in Pichia pastoris.

The C1 and C2 alcohols hold great promise as substrates for biomanufacturing due to their low cost and rich resources. Pichia pastoris is considered a preferred host for methanol and ethanol bioconversion due to its natural utilization of methanol and ethanol. However, the scarcity of strong and tightly regulated alcohol-inducible promoters limits its extended use. This study aimed to develop enhanced methanol- and ethanol-inducible promoters capable of improving gene expression in P. pastoris. Rational design strategies were employed to rewire the upstream regulatory sequence of the methanol-inducible PAOX1, generating several high-strength methanol-inducible promoters with a stringent regulatory pattern. Eleven strong promoters were identified from 36 endogenous ethanol-inducible candidates recognized from transcriptome analysis. Core promoter regions, the crucial element influencing transcriptional strength, were also characterized. Five high-activity core promoters were then combined with four upstream regulatory sequences of high-strength promoters, resulting in four groups of synthetic promoters. Ultimately, the highly active methanol-inducible PA13 and ethanol-inducible P0688 and PsynIV-5 were selected for the expression of an α-amylase and yielded enzyme activity 1.6, 2.6, and 4.5 times higher as compared to that of PAOX1. This work expands the genetic toolkit available for P. pastoris, providing more precise and efficient options for regulating gene expression. It benefits the use of P. pastoris as an efficient platform for the C1 and C2 alcohol-based biotransformation in industrial biotechnology.IMPORTANCEP. pastoris represents a preferred microbial host for the bio-utilization of C1 and C2 alcohols that are regarded as renewable carbon sources based on clean energy. However, lack of efficient and regulated expression tools highly limits the C1 and C2 alcohols based bioproduction. By exploring high-strength and strictly regulated alcohol-inducible promoters, this study expands the expression toolkit for P. pastoris on C1 and C2 alcohols. The newly developed methanol-inducible PA13 and ethanol-inducible PsynIV-5 demonstrate significantly higher expression levels than the commercial PAOX1 system. The endogenous and synthetic promoter series established in this study provides new construction references and alternative tools for expression control in P. pastoris for C1 and C2 alcohols based biomanufacturing.

Crystal defects Boost cellulose conversion to C2 alcohols over Pd/WO3 catalysts

Converting cellulose into C2 alcohols presents a sustainable alternative to fossil fuels, contributing to the development of eco-friendly and economically viable biofuels and chemicals. Tungsten oxide (WO3) is a key solid acid catalyst for this process, yet limited research explores its diverse morphologies and unique catalytic effects. This study investigates diverse WO3 morphologies (nanosheets, nanoflowers, nanoblocks, and tetrahedral octahedra) in combination with Pd for converting cellulose to C2 alcohols. Optimized conditions with Pd/o-WO3 catalyst resulted in the highest C2 alcohols (ethylene glycol and ethanol, 80.9 %), notably yielding 64.8 % ethylene glycol. Extensive characterizations and DFT calculations reveal the smaller element occupancy rates and a longer W-O bond length led to a large number of crystal defects over Pd/o-WO3. It facilitated the formation of W5+–OH sites and Pd-O(H)-W interactions, further synergistically enhancing hydrogenation ability and acidity. Designed experiments to elucidate cellulose conversion pathways, including hydrolysis, retro-aldol condensation, and hydrogenation. This study emphasizes the unique impact of WO3 morphologies and underscores the importance of supporting crystal defects for catalytic performance in eco-friendly biofuel and chemical production.

Concentrated C2+ Alcohol Production Enabled by Post-Intermediate Modulation and Augmented CO Adsorption in CO Electrolysis.

The electrocatalytic synthesis of multicarbon products from CO2/CO feedstock represents a sustainable method for chemical production with a reduced carbon footprint. Traditional copper catalysts predominantly produce alkenes, but generating valuable and versatile C2+ alcohols, especially high-energy-density C3 alcohols, has been challenging due to issues with selectivity, activity, and stability. Here, we present the construction of Ru-doped Cu nanowires that enhance the selectivity of n-PrOH and C2+ alcohols. In situ Raman spectroscopy shows that our approach promotes both *CO binding and availability, particularly facilitating the formation of high-frequency-bound *CO (*COHFB) and maintaining multiple *CO adsorption modes on Ru-modified and bare low-coordinated Cu nanowires. Density-functional theory (DFT) simulations illustrate that introducing Ru species onto a low-coordinated Cu step surface simultaneously stabilizes CO and alcohol-related intermediates, shifting the dominant reaction pathway toward alcohols and facilitating CO-C2 coupling at the expense of ethylene selectivity. In an alkaline gas-diffusion electrolyzer, we attained a maximum Faradaic efficiency (FE) of 35.9% for n-PrOH and 62.4% for the total C2+ alcohols. Optimizing parameters in the membrane electrode assembly (MEA) system enabled the one-pot generation and separation of C2+ alcohols, achieving a record concentration of 18.8 wt % (4.2 wt % n-PrOH and 14.6 wt % EtOH) with nearly 100% purity at 200 mA/cm2 over 100 h. This work not only provides new insights and guidance for the development of future catalysts from the perspectives of surface science and mechanisms but also highlights the importance of coupling material engineering with reactor engineering to optimize the production process of high-value alcohol products.

Electrolysis of low-carbon methanol for point-of-use hydrogen generation: Opportunities and challenges for the direct use of unrefined feedstocks

Low-carbon methanol (LCM) is a promising hydrogen carrier that can reduce the overall transportation and storage costs associated with the industrial use of H2 as a chemical feedstock or fuel. Herein, LCM refers to methanol produced via processes that emit lower greenhouse gases (by 90% or more) relative to conventional methanol production derived from fossil fuels like pipelined natural gas or coal. LCM production pathways can valorize stranded methane as well as from sources such as biomass and biogas (e.g., landfill and digester gases). The distributed nature of these stranded feedstocks lends themselves well to methanol synthesis within a smaller-scale, decentralized infrastructure. While process intensification and relatively cheaper feedstock can support these distributed productions, forgoing economies of scale can significantly increase the cost of conventional upgrading steps such as distillation. Fortunately, these upgrading steps may be unnecessary by targeting specific applications, where high methanol purities are not required, thereby lowering the holistic cost and carbon intensity of an overall process.Here, we consider methanol as a hydrogen carrier and its conversion to H2 at the point of use through an electrolytic process by experimentally comparing the oxidation of methanol, of varying purity levels (e.g., grade (99.9+% purity) and crude forms) using a proton exchange membrane (PEM) electrolyzer. In this study, the supply of crude methanol derives from a distributed gas-to-liquid process, developed by M2X Energy Inc. The impurity content is speciated and quantified within the crude methanol sample, which is used directly with water co-reactants to evaluate the effect of impurity type and concentration on electrolytic performance on commercial Pt–Ru catalysts. Our experimental results show that about 1 wt% of C2–C5 alcohols in the starting crude methanol readily poison the catalyst, leading to an increased electricity consumption by 5.1–9.8 kWh per kg H2 produced when operating the electrolyzer at high current densities (>200 mA cm−2). A sensitivity analysis is developed according to the measured energy penalty, which can be used to decide whether bypassing methanol distillation provides economic benefit based on site-specific electricity and distillation costs.

Interface-rich porous Fe-doped hcp-PtBi/fcc-Pt heterostructured nanoplates enhanced the C[sbnd]C bond cleavage of C3 alcohols electrooxidation

Efficient CC bond cleavage and the complete oxidation of alcohols are key to improving the efficiency of renewable energy utilization. Herein, we successfully prepare porous Fe-doped hexagonal close-packed (hcp)-PtBi/face-centered cubic (fcc)-Pt heterostructured nanoplates with abundant grain/phase interfaces (h-PtBi/f-Pt@Fe1.7 PNPs) via a simple solvothermal method. The open porous structure, abundant grain/phase interface and stacking fault defects, and the synergistic effect between intermetallic hcp-PtBi and fcc-Pt make h-PtBi/f-Pt@Fe1.7 PNPs an effective electrocatalyst for the glycerol oxidation reaction (GOR) in direct glycerol fuel cells (DGFCs). Notably, the h-PtBi/f-Pt@Fe1.7 PNPs exhibit an excellent mass activity of 7.6 A mgPt−1 for GOR, 4.75-fold higher than that of commercial Pt black in an alkaline medium. Moreover, the h-PtBi/f-Pt@Fe1.7 PNPs achieve higher power density (125.8 mW cm−2) than commercial Pt/C (81.8 mW cm−2) in a single DGFC. The h-PtBi/f-Pt@Fe1.7 PNPs can also effectively catalyze the electrochemical oxidation of 1-propanol (17.1 A mgPt−1), 1,2-propanediol (7.2 A mgPt−1), and 1,3-propanediol (5.2 A mgPt−1). The in-situ Fourier-transform infrared spectra further reveal that the CC bond of glycerol, 1-propanol, 1,2-propanediol, and 1,3-propanediol was dissociated for the complete oxidation by the h-PtBi/f-Pt@Fe1.7 PNPs. This study provides a new class of porous Pt-based heterostructure nanoplates and insight into the intrinsic activity of different C3 alcohols.

Lactiplantibacillus plantarum inoculation enhanced the color stabilization and aroma quality of blueberry wine

Inoculation of Lactiplantibacillus plantarum before yeast has the potential to affect the blueberry wine quality. The effects of four L. plantarum strains on the anthocyanins and volatile profile of blueberry wine were studied. Different L. plantarum inoculated wines presented a great color variation, and B3 strain was able to retain more bluish hue of blueberry wine. Compared with RF wine fermented by only Saccharomyces cerevisiae yeast, L. plantarum inoculated wines exhibited a better preservation of monomeric and acylated anthocyanins. More importantly, inoculation of L. plantarum, especially for B3 and B4 strains, enhanced the accumulation of pyranoanthocyanins, which may improve the color stability of blueberry wine. In addition, inoculation with L. plantarum favored the formation of lactate-related esters, acetoin, C6 alcohols, terpenes, aldehydes, and volatile phenols. Flash-Profile analysis indicated that B3, B4 and SS6 strains conferred wines more sour and astringent tastes, along with more ‘fruity’ and ‘chemical’ aromas.

Multiscale Computational Study of Cellulose Acetate-Water Miscibility: Insights from Molecularly Informed Field-Theoretic Modeling.

Cellulose acetate (CA), a prominent water-soluble derivative of cellulose, is a promising biodegradable ingredient that has applications in films, membranes, fibers, drug delivery, and more. In this work, we present a molecularly informed field-theoretic model for CA to explore its phase behavior in aqueous solutions. By integrating atomistic details into large-scale field-theoretic simulations via the relative entropy coarse-graining framework, our approach enables efficient calculations of CA's miscibility window as a function of the degree of substitution (DS) of cellulose hydroxyl groups with acetate side chains. This allows us to capture the intricate phase behavior of CA, particularly its unique miscibility at intermediate substitution, without relying on experimental input. Additionally, the model directly probes CA solution behavior specific to the relative DS at C2, C3, and C6 alcohol sites, providing insights for the rational design of water-soluble CA for diverse applications. This work demonstrates a promising integration of molecularly informed field theories, complementing wet-lab experimentation, for engineering the next-generation polymeric materials with precisely tailored properties.

Theoretical kinetics study of key reactions between ammonia and fuel molecules, part II: H-atom abstraction from alcohols and ethers by ṄH2 radicals

Ammonia, as a carbon-free fuel, is expected to be a carbon-neutral alternative fuel to control pollution emissions. However, with lower reactivity, pure ammonia needs to be blended with highly reactive biofuels including alcohols and ethers, for a better combustion performance. Alcohols and ethers can be produced from various sources, including renewable materials and fossil fuels. Therefore, the combination of ammonia with alcohols/ethers is a promising choice for developing carbon-neutral energy solutions. As an important intermediate, ṄH2 radicals can easily be formed during the pyrolysis or oxidation processes for ammonia combustion. The H-atom abstraction reaction between ṄH2 radicals and fuel molecules is vital in determining the blending fuel reactivity. High-level ab initio calculations have been carried out in this study to perform a systematic theoretical chemical kinetic investigation of H-atom abstraction by ṄH2 radicals from C1–C5 alcohols, 2,3-dimethyl-2-butanol, C1–C4 ethers and methyl isobutyl ether with a total of 61 H-atom abstraction reaction channels. The QCISD(T)/CBS//M06–2X/6–311++G(d, p) level of theory was employed to investigate the potential energy surfaces of the title reactions involved. Electronic geometry optimization, frequency analysis, and zero-point energy correction were performed for reactants, transition states and products related to 61 reaction channels at the M06–2X/6–311++G(d, p) level of theory. Single-point energy calculations were performed at the QCISD(T)/cc-pVXZ (X = D, T) and MP2/cc-pVYZ (Y = D, T, Q) level of theory and then extrapolated to the complete basis set. Conventional transition state theory was used to calculate the rate constants for different channels in the temperature range from 500 to 2000 K. The calculated individual and average rate constants for H-atom abstraction from different sites of alcohols and ethers were also obtained to explore the kinetic influence from the functional group. This is the first systematic study providing the rate constants for the title reactions which can be used to develop the combustion kinetic models for ammonia/alcohols and ammonia/ethers blends.

Evolution of Aroma Profiles in Vitis vinifera L. Marselan and Merlot from Grapes to Wines and Difference between Varieties.

The fermentation process has a significant impact on the aromatic profile of wines, particularly in relation to the difference in fermentation matrix caused by grape varieties. This study investigates the leaching and evolution patterns of aroma compounds in Vitis vinifera L. Marselan and Merlot during an industrial-scale vinification process, including the stages of cold soak, alcohol fermentation, malolactic fermentation, and one-year bottle storage. The emphasis is on the differences between the two varieties. The results indicated that most alcohols were rapidly leached during the cold soak stage. Certain C6 alcohols, terpenes, and norisoprenoids showed faster leaching rates in 'Marselan', compared to 'Merlot'. Some branched chain fatty-acid esters, such as ethyl 3-methylbutyrate, ethyl 2-methylbutyrate, and ethyl lactate, consistently increased during the fermentation and bottling stages, with faster accumulation observed in 'Marselan'. The study combines the Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) model based on odor activity values to elucidate the accumulation of these ethyl esters during bottle storage, compensating for the reduction in fruity aroma resulting from decreased levels of (E)-β-damascenone. The 'Marselan' wine exhibited a more pronounced floral aroma due to its higher level of linalool, compared to the 'Merlot' wine. The study unveils the distinctive variation patterns of aroma compounds from grapes to wine across grape varieties. This provides a theoretical framework for the precise regulation of wine aroma and flavor, and holds significant production value.

Combined effects of ferric oxide nanoparticles and C2–C4 alcohols with diesel/biodiesel blend on diesel engine operating characteristics

This study investigated the effects of using ferric oxide nanoparticles (FO) and C2–C4 alcohols with diesel/biodiesel blend in a diesel engine. Optimum operating conditions were explored, and an engine speed of 1750 rpm was optimal. The concentration of FO was estimated to be 760 ppm, considering the best conditions for carbon nanotube (CNT) production. Ethanol was immiscible in diesel fuel; however, any biodiesel percentage in the blend made it miscible. The used engine was too small to run with a blend containing more than 3 % ethanol. Propanol and butanol were blended at the same ethanol concentration for comparative purposes. A blend with 30 % biodiesel (B30) was found to be the best diesel/biodiesel blend. This was detected by the best coefficient of variation (COV) with reasonable performance and emissions. Ferric oxide nanoparticles reduced COV and improved engine performance. The COV increased for tested alcohols. However, blending B30 with alcohols, especially butanol, improved thermal efficiency. FO and alcohol increased NOx emissions and decreased both CO and smoke opacity. They increased the peak pressure and the heat release rate while reducing the combustion duration. Nonetheless, no CNT traces were detected in the present study under any conditions.

Influences of Cluster Thinning on Fatty Acids and Green Leaf Volatiles in the Production of Cabernet Sauvignon Grapes and Wines in the Northwest of China.

Cluster thinning has been widely applied in yield management and its effect on green leaf volatiles (GLVs) in wines has seldom been studied. GLVs are important flavor compositions for grapes and wines. This work aimed to investigate the impact of cluster thinning on these volatiles and their precursors in grapes and wines. Severe cluster thinning (CT1) and medium cluster thinning (CT2) were performed on Cabernet Sauvignon (Vitis vinifera L.) vines in two sites (G-farm and Y-farm) from Xinjiang province in the Northwest of China. The impact of cluster thinning treatments on the accumulation of GLVs and their precursors, long chain fatty acids (LCFAs) of grape berries and C6 volatiles, in resulting wines was investigated. Multivariate analysis showed that cluster thinning treatments induced significant changes in fruit and wine composition in both farms. In Y-farm, medium cluster thinning (CT2) significantly increased the average cluster weight of harvested berries. Additionally, both cluster thinning treatments (CT1 and CT2) increased fatty acids in harvested berries and CT2 led to an increase in C6 esters and a decrease in C6 alcohols in the wines of Y-farm under the warmer and drier 2012 vintage. However, the effect of cluster thinning was likely negative in G-farm due to its wetter soil and excessive organic matter. The treatments may be applicable for local grape growers to improve viticultural practices for the more balanced vegetative and reproductive growth of Cabernet Sauvignon grapevines. This work also provided further knowledge on the regulation of fatty acids and the derived C6 volatiles through the lipoxygenase (LOX) pathway.

Lamellar polyaniline-modified reduced graphene oxide loaded electron-rich Pd nanoparticles for highly efficient electrooxidation of C2 alcohols

Design and preparation of catalysts with lower cost and higher catalytic efficiency are still important strategy to promote the wide application of alkaline direct alcohol fuel cells (ADAFCs). In this study, a novel anode catalyst for ADAFCs has been easily synthesized based on polyaniline (PANI)-modified wrinkled reduced graphene oxide (rGO) and Pd nanoparticles (Pd NPs). Morphology and structure characterization confirm the modified lamellar structure and composition of the Pd/PANI-rGO composite, and X-ray photoelectron spectroscopy (XPS) demonstrates the electron transfer from PANI-rGO to Pd NPs. For ethylene glycol and ethanol oxidation reactions (EGOR/EOR) in alkaline media, the Pd/PANI-rGO exhibits promising electrocatalytic properties with mass activity as 4342.5 and 2220.4 mA mgPd-1, specific activity as 26.6 and 13.6 mA cm-2 and intrinsic activity as 5.7 and 2.5 s-1, respectively. Moreover, the Pd/PANI-rGO shows significantly enhanced anti-poisoning ability and durability as compared with contrast samples due to the well dispersion of Pd NPs on PANI-rGO and the synergistic interaction between PANI-rGO and Pd NPs producing electron-rich Pd and more active sites for EGOR and EOR. This work is expected to provide theoretical foundation for designing low-cost and high-efficiency ADAFCs anode catalysts.

Analysis of Volatile Aroma Components in Different Parts of Shiitake Mushroom (Lentinus edodes) Treated with Ultraviolet C Light-Emitting Diodes Based on Gas Chromatography-Ion Mobility Spectroscopy.

Further assessment of ultraviolet C light-emitting diode (UVC-LED) irradiation for influencing shiitake mushrooms' (Lentinus edodes) volatile and sensory properties is needed. In this study, a comparison of UVC-LED irradiation treatment on the flavor profiles in various parts of shiitake mushrooms was conducted using gas chromatography-ion mobility spectrometry (GC-IMS) and sensory analysis. Sixty-three volatile compounds were identified in shiitake mushrooms. The fresh shiitake mushrooms were characterized by the highest values of raw mushroom odors. After UVC-LED treatment, the content of C8 alcohols decreased, especially that of 1-octen-3-ol, while the content of aldehydes increased, especially the content of nonanal and decanal. The score of fatty and green odors was enhanced. For fresh samples, the mushroom odors decreased and the mushroom-like odors weakened more sharply when treated in ethanol suspension than when treated with direct irradiation. The fruit odors were enhanced using direct UVC-LED irradiation for fresh mushroom samples and the onion flavor decreased. As for shiitake mushroom powder in ethanol suspension treated with UVC-LED, the sweaty and almond odor scores decreased and the vitamin D2 content in mushroom caps and stems reached 668.79 μg/g (dw) and 399.45 μg/g (dw), respectively. The results obtained from this study demonstrate that UVC-LED treatment produced rich-flavored, quality mushroom products.

Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions.

A skeletal rearrangement of a series of 6,8-dioxabicyclo[3.2.1]octan-4-ols has been developed using SOCl2 in the presence of pyridine. An oxygen migration from C5 to C4 was observed when the C4 alcohols were treated with SOCl2/pyridine, giving a 2-chloro-3,8-dioxabicyclo[3.2.1]octane ring-system via the chlorosulfite intermediate. Analogous allylic alcohols with endocyclic and exocyclic unsaturations underwent chlorination without rearrangement due to formation of allylic cations. The rearrangement was also demonstrated using Appel conditions, which gave similar results via the alkoxytriphenylphosphonium intermediate. Several reactions of the products were investigated to show the utility of the rearrangement.

Vineyard microclimate alterations induced by black inter-row mulch through transcriptome reshaped the flavoromics of cabernet sauvignon grapes

BackgroundWeed control is essential for agricultural floor management in vineyards and the inter-row mulching is an eco-friendly practice to inhibit weed growth via filtering out photosynthetically active radiation. Besides weed suppression, inter-row mulching can influence grapevine growth and the accumulation of metabolites in grape berries. However, the complex interaction of multiple factors in the field challenges the understanding of molecular mechanisms on the regulated metabolites. In the current study, black geotextile inter-row mulch (M) was applied for two vintages (2016–2017) from anthesis to harvest. Metabolomics and transcriptomics analysis were conducted in two vintages, aiming to provide insights into metabolic and molecular responses of Cabernet Sauvignon grapes to M in a semi-arid climate.ResultsUpregulation of genes related to photosynthesis and heat shock proteins confirmed that M weakened the total light exposure and grapes suffered heat stress, resulting in lower sugar-acid ratio at harvest. Key genes responsible for enhancements in phenylalanine, glutamine, ornithine, arginine, and C6 alcohol concentrations, and the downward trend in ε-viniferin, anthocyanins, flavonols, terpenes, and norisoprenoids in M grapes were identified. In addition, several modules significantly correlated with the metabolic biomarkers through weighted correlation network analysis, and the potential key transcription factors regulating the above metabolites including VviGATA11, VviHSFA6B, and VviWRKY03 were also identified.ConclusionThis study provides a valuable overview of metabolic and transcriptomic responses of M grapes in semi-arid climates, which could facilitate understanding the complex regulatory network of metabolites in response to microclimate changes.

Functionalized ligands mediated microenvironment of Pd@UiO-66-X catalysts for ethanol upgrading to n-butanol

The upgrading of ethanol to produce n-butanol and other >C4 alcohols is a promising reaction. However, the development of efficient catalysts for this reaction has been slow. In this study, we prepared a series of Pd@UiO-66-X catalysts using ligands functionalized with electron-donating groups (–NH2 and –CH3) and electron-accepting groups (–H and –NO2). These functional groups play two roles in mediating the microenvironment of the Pd metal. Firstly, they regulate the electronic properties of the Pd metal, and secondly, they alter the hydrophilicity/hydrophobicity surrounding the Pd metal. The intrinsic electronic properties of the Pd metal significantly influence ethanol conversion, while the hydrophilicity/hydrophobicity surrounding the Pd metal is an extrinsic factor. As a result, the Pd@UiO-66-CH3 catalyst with a hydrophobic microenvironment around the electron-rich Pd metal exhibits the highest ethanol conversion and n-butanol yield among all the Pd@UiO-66-X catalysts. It also achieves an impressive >C4 alcohols yield of up to 47.7 %, which is the highest reported to date.

Highly efficient catalytic oxidation of toluene by amorphous/microcrystalline mixed-phase MnO2

Amorphous transition metal oxides exhibit considerable potential in the catalytic oxidation of volatile organic compounds (VOCs) owing to their distinctive surface properties. In this study, we achieved the modulation of the crystalline structure of manganese oxides by employing various C3 alcohols (alcohols with three carbons) with distinct hydroxyl types during the reduction process with potassium permanganate. Subsequently, a series of characterization techniques were employed to assess the catalytic performance of the prepared MnO2 in the oxidation of toluene. Notably, the MnO2-G obtained from glycerol presented excellent catalytic activity (T90 = 219 °C), stability, and water resistance. The unique amorphous/microcrystalline state of MnO2-G exposed more phase boundaries, and the unsaturated coordination structure facilitated the generation of additional defective sites, favoring the adsorption and activation of oxygen. Furthermore, the mixed-crystalline state induced the elevated Mn3+ content on the surface of MnO2-G, leading to elongation of the Mn-O bond due to the pronounced Jahn-Teller effect of Mn3+. Consequently, the synergistic effects of the mixed crystalline state contributed to the efficient catalytic oxidation of toluene at relatively low temperatures. Additionally, the conversion pathway of toluene on MnO2-G was further revealed by in situ DRIFTS.

Experimental Investigation of Glycerol Derivatives and C1–C4 Alcohols as Gasoline Oxygenates

Certain oxygenated compounds, when blended with gasoline, have the ability to inhibit the occurrence and decrease the intensity of engine knock, helping improve engine efficiency. Although ethanol has had widespread use as an oxygenate, higher alcohols, such as butanol, exhibit superior properties in some respects. Besides alcohols, glycerol derivatives such as glycerol tert-butyl ether (GTBE), among others, also have the potential to be used as gasoline oxygenates. This work provides a direct comparison, performed on a modified Waukesha CFR engine, of C1–C4 alcohols and the glycerol derivatives GTBE, solketal, and triacetin, all blended with a gasoline surrogate in different concentrations. The tests focused on how these oxygenated compounds affected the knocking behavior of the fuel blends, since it directly impacts engine efficiency. The test matrices comprised spark-timing sweeps at two different compression ratios, at stoichiometric conditions and constant engine speed. The results showed that, in general, the C1–C4 alcohols and the glycerol derivatives were effective in decreasing knock intensity. n-Butanol and solketal were the noteworthy exceptions, due to their demonstrated inferior knock-inhibiting abilities. On the other hand, isopropanol, isobutanol, and GTBE performed particularly well, indicating their potential to be used as gasoline oxygenates for future engines, as alternatives to ethanol.

Zirconia-incorporated yttria with a Lewis pair of acid–base surface sites for chemoselective dehydration of alcohols into alpha olefins

Alpha olefins are currently made by ethylene oligomerization to a broad range of carbon number. An alternative conversion is selective alcohol dehydration in which the conventional catalyst development focused on the addition of any basic components into acidic supports. We herein demonstrated that the Zr4+ addition to Y2O3 (acid-to-base addition) was more effective than the Y3+ addition to ZrO2 in alcohol dehydration to alpha olefins. The zirconia-incorporated yttria with 4 mol% Zr (named 4ZIY) was structurally more stable than the yttria-stabilized zirconia (YSZ) counterpart. Moreover, the 4ZIY showed a high purity of alpha olefins when various C4 and C6 alcohols were used. Catalyst characterization works revealed that the 4ZIY contains a large amount of strong Lewis base sites, which is associated with oxygen vacancy, with a little Lewis acid sites. Consequently, the 4ZIY is suggested to have the favorable acid–base pair for the conversion of alcohols to alpha olefins.