Hydrolysis Of Acetate Research Articles

Prevalence and antibiotics susceptibility of thermotolerant <i>Campylobacter</i> spp. isolated from humans and chickens in the Republic of Guinea

Background.The issue of diarrheal diseases remains relevant for modern health care in all countries. Campylobacteriosis is the most common infectious disease with foodborne transmission and poultry meat is a transmission factor.Materials and methods.724 items of faeces sampled from patients with diarrheal syndrome and 283 samples of faeces of chickens raised on private farms and five poultry farms in the province were studied. For bacteriological method were used selective media. Traditional routine tests (cell morphology, cytochrome oxidase, catalase, hydrolysis of sodium hippurate and indoxyl acetate) and MALDI-ToF mass spectrometry was performed for identification. The susceptibility of strains to antibiotics was analysed using the disc-diffusion method. Results were interpreted according to the EUCAST criteria, versions 2019–2022.Results.Campylobacterspp. was cultured in 65 out of 724 faecal samples from patients with acute diarrhoea, of them 83.08% were identified asC. jejuni, and 16.92% asC. coli. Of the 237Campylobacterstrains from chicken were identified asC. jejuni(54.0%), asC. coli(46.0%).Campylobacterspp. strains from humans were resistant to tetracycline (40.0%), to erythromycin (6.15%), to ciprofloxacin (12.31%). The strains from chickens kept on farms, were resistant to tetracycline in 42.55%, to ciprofloxacin — in 22.70% and to erythromycin — in 11.35%. The strains from chickens kept on private farms were resistant to tetracycline in 4.17%, to ciprofloxacin — in 1.04%, all strains were sensitive to erythromycin.Conclusion.Thus, due to the widespread prevalence ofCampylobacterspp., infectious diseases they cause remain a topical issue. Studying the resistance to antibiotics inCampylobacterspp. among poultry could allow to develop new approaches to confirming the significance of their foodborne nature and to improve the national disease prevention system.

DEVELOPMENT OF DRY BUILDING MIXTURES BASED ON REDISPERSIBLE POWDER FOR REGULATING THE PROPERTIES OF PLASTER MIXTURES

The relevance of the work. The results is theoretically substantiated and experimentally confirmed the possibility of obtaining a dry additive-retarder of gypsum setting based on lime and polyvinyl acetate dispersions due to the formation of polyvinyl alcohol and salts of calcium acetate in the result of alkaline hydrolysis of polyvinyl acetate dispersion (PVAD) with the slaked lime in hydrated lime. The results of the work implemented in the production of dry gypsum mixes. Purpose. The development of dry building mixes based on gypsum and time increase of time of their conformance through adding of complex additives on the basis of burnt lime and polyvinyl acetate dispersions [PVAD]. Methodology. The study used standard research techniques to determine physical and mechanical properties of gypsum binders and quality of complex additives according to ДСТУ Б В.2.7-82:2010, ДСТУ Б В.2.7-23-95, ДСТУ Б В.2.7-171:2008. Study of phase composition of materials, micro – and macrostructure was carried out by x-ray diffraction, electron and light microscopy. The results. The influence of the main components of the additive (polyvinyl acetate dispersion and lime) on the properties of hemihydrate gypsum is investigated. The chemistry of the interaction of components of the complex additive, according to which the result of alkaline hydrolysis of polyvinyl acetate is formed: polyvinyl alcohol, a feature of its molecules structure is the presence of hydrophilic OH−groups and the hydrophobic component − a hydrocarbon radical. The hydrophilic part of the molecule being ion adsorbed on the surface of the particles of the binder, forms a monomolecular layer that is oriented with the hydrophobic part of the gypsum particles. It is also possible the formation of calcium acetate Ca(СН3СОО)2, which increases the concentration of calcium ions in solution. The combined effect of hydrolysis products significantly reduce the solubility of hemihydrate, the rate of formation of crystallization centers, due to the slowing effect of these supplements.

Antimicrobial Activity of ZnS and ZnO-TOP Nanoparticles Againts Pathogenic Bacteria.

This study aims to synthesize ZnS nanoparticles (NPs) and investigate their biocidal effects, along with those of ZnO-Trioctylphosphine (ZnO-TOP) NPs, on various pathogenic microbes. The NPs were synthesized via the polyol method using the forced hydrolysis of zinc acetate. They were characterized by XRD and TEM. The average sizes of ZnS and ZnO-TOP are 3.63 nm and 16.28 nm, respectively. The antimicrobial activities were assessed using agar-well diffusion, minimum inhibitory concentration (MIC), and biofilm inhibition. The results showed that ZnS and ZnO-TOP NPs have potent antimicrobial activity against all tested pathogen microbes. A zone of maximum inhibition (ZMI) of 20±0.54 and 22±0.26 was observed in the case of ZnS for Acinetobacter baumannii and Candida albicans, respectively. For ZnO-TOP, a ZMI of 20±0.15 and 20±0.19 is obtained for Pseudomonas. aeruginosa ATCC 27853 and A. baumannii, respectively. Percentages of biofilm inhibition at 128 μg/ml were notably high for Enterococcus faecalis (96.83 % with ZnO-TOP and 91.17 % with ZnS) and Staphylococcus aureus (87.27 % with ZnO-TOP and 76.37 % with ZnS). The results suggest that ZnS and ZnO-TOP nanoparticles have promising potential as effective antimicrobial agents, especially against biofilm-forming pathogens, indicating their potential for future use in treating microbial infections.

Challenging design of highly active Pt/CeO2–TiO2/ZSM-5 catalysts for VOCs low-temperature removal

Four Pt/CeO2–TiO2/ZSM-5 catalysts with different Pt species dispersion states and acidic properties were designed, and key factors affecting the oxidation activity of various VOCs (benzene, DCE, ethyl acetate and acetonitrile as typical organic compounds of aromatic hydrocarbon and halogen/oxygen/nitrogen-containing VOCs, respectively) were identified in the present work. The strength of the acid and oxidation sites on the surface of catalysts and their synergistic interaction play a crucial role. Highly dispersed Pt species and its strong redox ability promote low-temperature oxidation of benzene. A synergistic interaction between the acid and oxidation sites is required to achieve high DCE oxidation activity. An abundance of surface acid sites (particularly strong acid sites) favors the adsorption and dechlorination to form vinyl chloride of DCE, and the strong redox ability of oxidation sites would accelerate the deep oxidation of intermediates (such as vinyl chloride and acetic acid, etc.). For ethyl acetate or acetonitrile oxidation, the strong acidic property of the catalyst plays a prior role for their catalytic oxidation, which facilitates the low-temperature hydrolysis of ethyl acetate or acetonitrile. This work provides a significant thought to design and synthesize high activity catalysts for low-temperature oxidation of various VOCs pollutants.

Novel Rhizophus oryzae esterase-immobilized chitosan/carbon nanomaterials as sensing support for enzyme inhibition-based biosensor in the detection of organophosphorus pesticide residues on crops

The use of mobile biosensor would allow for cost-effective and rapid on-site detection of organophosphorus (OP) pesticide. Immobilizing enzyme on electrode would improve the sensitivity of biosensor due to the nature of its specific active site-binding. OP inhibition on esterase enzyme is used as the sensing mechanism of the biosensor. In this study, microbial esterase from Rhizopus oryzae (RoE) was immobilized into modified screen-printed carbon electrode (SPCE) for the fabrication of novel RoE/chitosan/nanomaterial-COOH/SPCE biosensor for the detection of methyl parathion, an OP pesticide. The first phase of this study aims to analyze biochemical characteristics of 1-naphthyl acetate (1-NA) hydrolysis by RoE and enzymatic inhibition of RoE by OP pesticide. RoE kinetic showed the best fit with Langmuir model with the highest linear regression (R2 = 0.996). The inhibition of RoE by OP was shown to be linearly proportional to the enzyme activity (R2 = 0.827). The second phase of this study aims to analyze electrochemical performance of RoE-immobilized biosensor. Various carbon-based sensing support nanomaterials (graphene nanoplatelets (GNP), graphite and multi-walled carbon nanotube (MWCNT)) was functionalised by carboxyl (-COOH) group and screened, where all nanomaterials showed effective sensitivity towards detecting 0.01 ng/L methyl parathion pesticide. GNP-based biosensor exhibited the highest degree of inhibition (9.94 %) and better reproducibility after the first cycle. RoE/chitosan/GNP-COOH/SPCE biosensor is promising to be developed as cost-effective and highly sensitive biosensor for OP pesticide detection.

A Structural Mimic of Carbonic Anhydrase in Zeolitic Imidazolate Frameworks via Trans-functionalization for Enhancing Hydrolytic Activity.

Metal-organic frameworks (MOFs) have been widely considered as ideal platforms for the preparation of biomimetic catalysts, but it remains challenging to fabricate MOF-based enzyme-like catalysts with optimal activity. Here, we leverage the inherent flexibility of MOFs and propose a novel trans-functionalization strategy to construct a carbonic anhydrase (CA) mimic by the structural transformation from ZIF-L to ZIF-8. Theoretical and experimental results reveal that during the structural transformation, the hydroxyl group will preferentially coordinate with the interlayer Zn clusters to form the CA-like active center Zn-N3-OH. Therefore, more accessible active centers are generated on the as-prepared ZIF-8-OH, resulting in substantially enhanced catalytic activity in the hydrolysis of para-nitrophenyl acetate.

DEVELOPMENT OF A PAPER-BASED DEVICE USING INDOXYL ACETATE AS A CHROMOGENIC SUBSTRATE FOR RAPID QUALITATIVE DETERMINATION OF LIPASE INHIBITOR

An improved paper-based device using indoxyl acetate as a chromogenic substrate was developed for rapid qualitative determination of lipase inhibitory activity. Colorless indoxyl acetate can be catalytically hydrolyzed by lipase to produce the blue-colored indigo dimer on the paper device. In the presence of a lipase inhibitor, enzyme activity diminishes, resulting in reduced hydrolysis of indoxyl acetate. Consequently, this leads to a decrease in the intensity of the blue coloration, which can be visually observed across a range of blue shades and analyzed using image analysis. Orlistat was used as the representative lipase inhibitor in the assay. The LODs obtained from visual detection and the image analysis were comparable. The paper-based device using indoxyl acetate for lipase inhibition assay was simple and convenient. It could be useful as a simple screening method for the detection of orlistat adulteration in weight loss supplements.

Metal-modified CeO2 nanobelts for catalytic oxidation of ethyl acetate: Roles of surface lattice oxygen and hydrolysis behaviors

Based on the comparison of three counterparts [Mg-, Al- and Cu-modified CeO2 nanobelts], it is illustrated that the low-temperature hydrolysis of ethyl acetate (EA) rapidly occurs and the removal of absorbed hydrolyzates (mainly acetates) is considered the rate-determining step. As the temperature increases, the escape of surface lattice oxygen (Os-latt) breaks through the shield of hydrolyzates and promotes the deep oxidation of intermediate products. Additionally, the activated Os-latt also facilitates the C-O bond cleavage in EA by nucleophilic attack. Due to the Os-latt escape, surface metal ions achieve more unsaturated coordinations to absorb the CH3COO– species, leading to competitive adsorption between O2 and hydrolyzates. The Cu modification strengthens the coordination adsorption of CH3COO– species, and the Al modification exhibits a low Os-latt mobility. These factors all contribute to a strong adsorption or accumulation of surface hydrolyzates. Therefore, a favorable ester hydrolysis-oxidation process over CeO2-based catalysts depends not only on excellent Os-latt mobility but also the suitable adsorption capacity of hydrolyzates, such as Mg modification.

Multiple effects of relative humidity on heterogeneous ozonolysis of cooking organic aerosol proxies from heated peanut oil emissions

The exposure to cooking organic aerosols (COA) is closely related to people's daily lives. Despite extensive investigations into COA's model compounds like oleic acid, the intricacies of heterogeneous ozonolysis of real COA and the effects of ambient conditions like humidity remain elusive. In this work, the ozonolysis of COA proxies from heated peanut oil emissions was investigated using diffuse reflectance infrared Fourier transform (DRIFTS) spectroscopy, and proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS). We found that humidity hinders the reaction between ozone and CC double bonds due to the competitive adsorption of water and ozone on COA. Although visible light has little influence on the ozonolysis of COA in the absence of humidity, the ozonolytic CO production is significantly promoted by visible light in the presence of humidity. It may be attributed to the formation of water-derived reactive oxygen species (ROS, mainly HO•) from the photosensitization of polycyclic aromatic hydrocarbons (PAHs) in COA. We also found that humidity can enhance the depolymerization of carboxylic acid dimers and hydrolysis of intrinsic acetals in the COA. Moreover, humidity promotes the release of VOCs during both the dark and light ozonolysis of COA. This work reveals the important roles of humidity-responsive and photo-responsive components in COA during its ozonolysis, and the change in VOC release may guide the control of human VOC exposure in indoor air.

Alkaline hydrolysis of poly (ethylene terephthalate) using 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU)

Advanced polymer recycling methods can address challenges with mechanical recycling caused by contaminated samples and mixed plastic wastes. In this work, we report alkaline hydrolysis of poly (ethylene terephthalate) (PET) flakes using a super basic reagent, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) in an aqueous media. The effect of operating conditions including temperature, time, and DBU concentration on the conversion of PET and the yield of terephthalic acid (TPA) was investigated. The relative hydrolysis kinetics were compared for the homogenous reaction of ethyl acetate and heterogenous PET reaction to elucidate the mechanism. While DBU exhibited much higher activity for both systems than NaOH at similar conditions, the increase in rate kinetics was much greater for the PET hydrolysis. This difference in kinetics was attributed to a combination of improved surface wetting of PET by DBU reaction media and the increased activity of the DBU. The hydrolysis of ethyl acetate was studied as a model system to determine the reactant's activity in a homogenous hydrolysis reaction. The effect of surface wetting was studied by conducting contact angle measurements of solutions.

Silica Nanoparticles Functionalized with an Ionic Liquid: A Green and Efficient Heterogeneous Catalyst for a Cascade Reaction

AbstractA new strategy for a catalytic C−C bond forming cascade reaction comprising acetal hydrolysis and Knoevenagel condensation is presented here. The heterogeneous nanocatalyst is prepared by immobilizing an ionic liquid on the surface of highly monodisperse silica nanoparticles. This work is the first example of showing that there is no need to use bifunctional acid‐base catalysts for a cascade reaction including the hydrolysis of benzaldehyde dimethyl acetal to benzaldehyde and the subsequent Knoevenagel condensation of the resulting benzaldehyde with malononitrile. It is shown here that these reactions can proceed smoothly with a mono‐functional heterogeneous catalyst that contains a neutral ionic liquid. It has been proposed that such a neutral ionic liquid can “switch on” to an acidic catalyst in conjunction with water. The selected ionic liquid has potentially biodegradability characteristics, which is an important issue to achieve a sustainable catalyst. The simple procedure for preparing both the ionic liquid and the monodisperse silica nanoparticles provides opportunities for a large‐scale synthesis of the catalyst. This work introduces a breakthrough in the design and synthesis of heterogeneous catalysts for acid/base catalyzed cascade organic reactions.

Kinetic Study of the Esterase-like Activity of Albumin following Condensation by Macromolecular Crowding.

The ability of bovine serum albumin (BSA) to form condensates in crowded environments has been discovered only recently. Effects of this condensed state on the secondary structure of the protein have already been unraveled as some aging aspects, but the pseudo-enzymatic behavior of condensed BSA has never been reported yet. This article investigates the kinetic profile of para-nitrophenol acetate hydrolysis by BSA in its condensed state with poly(ethylene) glycol (PEG) as the crowding agent. Furthermore, the initial BSA concentration was varied between 0.25 and 1 mM which allowed us to modify the size distribution, the volume fraction, and the partition coefficient (varying from 136 to 180). Hence, the amount of BSA originally added was a simple way to modulate the size and density of the condensates. Compared with dilute BSA, the initial velocity (vi) with condensates was dramatically reduced. From the Michaelis-Menten fits, the extracted Michaelis constant Km and the maximum velocity Vmax decreased in control samples without condensates when the BSA concentration increased, which was attributed to BSA self-oligomerization. In samples containing condensates, the observed vi was interpreted as an effect of diluted BSA remaining in the supernatants and from the condensates. In supernatants, the crowding effect of PEG increased the kcat and catalytic efficiency. Last, Vmax was proportional to the volume fraction of the condensates, which could be controlled by varying its initial concentration. Hence, the major significance of this article is the control of the size and volume fraction of albumin condensates, along with their kinetic profile using liquid-liquid phase separation.

Fluorescent sensor for rapid detection of organophosphate pesticides using recombinant carboxylesterase PvCarE1 and glutathione-stabilized gold nanoclusters

Considering the severe threat to human health posed by organophosphate pesticides (OPs), reliable and rapid detection methods are urgently needed. In this study, we developed a straightforward and sensitive fluorescence sensor for OP detection. The sensor is based on glutathione-stabilized gold nanoclusters (GSH-AuNCs) and the inhibition of the recombinant carboxylesterase PvCarE1. The fluorescence signal of GSH-AuNCs is efficiently quenched by p-nitrophenol (p-NP) through inner filter effect, which is the product of the recombinant carboxylesterase PvCarE1-catalyzed hydrolysis of p-nitrophenol acetate (p-NPA). In the presence of OPs, the activity of the recombinant carboxylesterase PvCarE1 is inhibited, resulting in decreased p-NP production, and the fluorescence signal of the GSH-AuNCs is maintained. The assay exhibited good sensitivity to dichlorvos, trichlorfon, and profenofos, with detection limits of 0.2 μg/L, 5 μg/L, and 5 μg/L, respectively. In addition, the developed assay was applied to apple sample detection, with recoveries ranging from 84.5 % to 106.3 % and RSDs ranging from 1.3 % to 10.5 %, demonstrating its high potential in monitoring OPs in food.

Activity of carboxylesterase enzyme in different tissues of sixth instar larvae Orthaga exvinacea Hampson under various conditions of temperature and pH

The mango leaf-webber, Orthaga exvinacea Hampson is one of the major pests of mango crop. In larval stage, they defoliate the leaves and thereby reduce the crop yield but in adult stage, they do not cause any damage to the crop. Insect must chemically alter and dispose of a large variety of compounds to maintain their normal body function. They must neutralise, inactivate or eliminate many foreign substances including pesticides. All foreign organic compounds are susceptible to metabolic attack in vivo. This biotransformation may involve by the activity of some enzymes. Carboxylesterases are major enzymes involved in the resistance process in several insect species. The appraisal and hydrolytic capacity of these catalysts work best inside particular temperature and hydrogen ion concentration (pH) conditions. The impacts of temperature and pH on the hydrolysis of both α-naphthyl acetate and β-naphthyl acetate by Orthaga exvinacea carboxylesterase and the tissue fractionation of these enzymes were examined. The ideal conditions for measuring carboxylesterase movement of Orthaga exvinacea were pH of 6.6 - 7.2 and temperature 35°C - 45°C. The particular carboxylesterase action indicates most extreme behaviour at pH 6.8 and temperature at 40oC. Tissue confinement investigation of the enzyme in Orthaga exvinacea demonstrated the nearness of carboxylesterase action in every division.

Reliability of transparent conductive oxide in ambient acid and implications for silicon solar cells

Transparent conductive oxide (TCO) films, known for their role as carrier transport layers in solar cells, can be adversely affected by hydrolysis products from encapsulants. In this study, we explored the morphology, optical-electrical properties, and deterioration mechanisms of In2O3-based TCO films under acetic acid stress. A reduction in film thickness and carrier concentration due to acid-induced corrosion was observed. X-ray photoelectron spectroscopy and inductively coupled plasma emission spectrometry analyses revealed that TCOs doped with less-reactive metals exhibited enhanced corrosion resistance. The efficiency of silicon heterojunction (SHJ) solar cells with tin-doped indium oxide, titanium-doped indium oxide, and zinc-doped indium oxide films decreased by 10%, 26%, and 100%, respectively, after 200 ​h of corrosion. We also found that tungsten-doped indium oxide could effectively safeguard SHJ solar cells against acetic acid corrosion, which offers a potential option for achieving long-term stability and lower levelized cost of solar cell systems. This research provides essential insights into selecting TCO films for solar cells and highlights the implications of ethylene-vinyl acetate hydrolysis for photovoltaic modules.

Highly selective conversion of diols into aldehydes for the purification of ethylene glycol with a self-adjusting coupling reactor

A coupling reactor was designed to convert 1,2-propanediol and 1,2-butanediol in ethylene glycol, followed by hydrolysis of acetals and regeneration of ethylene glycol.

A new plant-esterase inhibition based electrochemical sensor with signal amplification by MoS2@N-CDs for chlorpyrifos detection.

Chlorpyrifos (CPF) is the most common pesticide entering the food chain and posing a threat to human health. This study presents a new electrochemical biosensor based on molybdenum disulfide nanosheets and nitrogen-doped carbon dot nanocomposite (MoS2@N-CDs) and kidney bean esterase (KdBE), and it is shown to achieve accurate detection of CPF. MoS2@N-CDs were prepared by a facile solvothermal method and characterized by electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Electrochemical characterization confirmed that MoS2@N-CDs facilitated electron transfer and increased the electroactive surface area of the electrode, thereby improved the sensing performance of the electrode. The oxidation peak current of 1-naphthol, which was produced by the hydrolysis of 1-naphthyl acetate catalyzed by KdBE, was adopted as the signal of the sensor. CPF can suppress KdBE activity and consequently cause a decrease in the sensing signal. The experimental results show that the variation of sensing signal is a reliable index to evaluate the CPF level. Under the optimized conditions, the developed enzyme sensor showed superior CPF assay performance with a linear detection range as wide as 0.01-500 μg L-1 and LOD as low as 3.5 × 10-3 μg L-1 (S/N = 3). The inter- and intra-batch RSDs for electrode testing were 4.02% and 2.69%, respectively. Moreover, the developed biosensor also showed good stability and anti-interference. The spiked recoveries of CPF in oilseed rape and cabbage ranged from 98.09% to 106.01% with low relative standard deviation (RSD) (<5.23%), suggesting that the sensor is a promising tool to enable simple, low-cost but highly sensitive large-scale screening of CPF residues in food.

Influence of Chemical Nature of Citric and Tartaric Acids on Reaction Time of the Crosslinking of Polyvinyl Alcohol Hydrogels.

Poly(vinyl alcohol) (PVOH) is a water-soluble polymer having a hydroxyl group as a functional group contributing to excellent membrane-forming and mechanical performance. PVOH is obtained by the hydrolysis of polyvinyl acetate, and its physical properties are affected by its degree of hydrolysis, whether, partial or complete. In this study, PVOH hydrogels were synthesized by a solution under stirring and heating techniques with citric (AC) and tartaric acids (AT) crosslinker agents, with different time reactions of 20 min.; 1; 2, and 3 h were investigated. These samples were characterized by the kinetics of water uptake, gel fraction, thermal analysis, and physical-chemical analysis, and their structure was elucidated. The results obtained have shown chemical modification by organic acids and improved the properties to good thermal stability and swelling to AT hydrogels up to 900% water uptake. In the gel fraction, the samples' esterification was shown and verified by FTIR spectra. To AC hydrogels the chemical modification was low due to the steric hindrance, which caused disintegration of the hydrogel in swelling and gel fraction test, but with absorption in the moisture test performed. The incorporation and effects of citric and tartaric acids enable the development of new hydrogel systems, with specific properties.

Longer fatty acid-protected GalNAz enables efficient labeling of proteins in living cells with minimized S-glyco modification.

Metabolic glycoengineering provides a powerful tool to label proteins with chemical tags for cell imaging and protein enrichment. The structures of per-O-acetylation on unnatural sugars facilitate membrane permeability and increase cellular uptake and are widely used for metabolic glycan labeling. However, unexpected S-glyco modification was discovered via a non-enzymatic reaction with protein cysteines, which was initially conducted with the hydrolysis of anomeric acetate by esterase. Herein, we synthesized a series of GalNAz derivatives that were protected with various lengths of short-chain fatty acid, including acetate, propionate, butyrate, valerate and pivalate, to detect differences in labeling efficiencies and occurrence of S-glyco modification. Our results demonstrate that all the GalNAz derivatives could effectively label proteins in HeLa cells, except the pivalate group. Of note, But4GalNAz exhibited excellent labeling abilities compared with Ac4GalNAz from the results for western blot, flow cytometry and confocal laser scanning microscopy. Moreover, the results for the S-glyco-modification assay by western blot and chemoproteomic analysis indicated that But4GalNAz generated negligible unexpected labeling signals compared to Ac4GalNAz. Our study uncovers the distinct labeling efficiency of different protected groups on unnatural sugars, which provides an alternative strategy to explore novel glycan probes.

Boosting the catalytic performance of Al2O3-supported Pd catalysts by introducing CeO2 promoters.

Maintaining the stability of noble metals is the key to the long-term stability of supported catalysts. In response to the instability of noble metal species at high temperatures, we developed a synergistic strategy of dual oxide supports. By designing and constructing ceria components with small sizes, we have achieved unity in the ability of catalytic materials to supply oxygen and stabilize metal species. In this study, we prepared Al2O3-CeO2-Pd (AlCePd) catalysts containing trace amounts of Ce through the hydrolysis of cerium acetate, which achieved 100% CO conversion at 160 °C. More importantly, the activity remained at its initial 100% in the long-term durability testing, demonstrating the high stability of AlCePd. In contrast, the CO conversion of the CeO2-Pd (CePd) catalyst decreased from 100% to 54% within 3 h. Through comprehensive studies, we found that this excellent catalytic performance stems from the stabilizing effect of an alumina support and the possible reverse oxygen spillover effect of small-sized ceria components, where small-sized ceria components provide active oxygen for independent Pd species, making it possible for the CO adsorbed on Pd to react with this oxygen species.