Topics in Catalysis最新文献

5-Hydroxymethylfurfural (HMF) is a crucial platform molecule derived from biomass, with the potential for conversion into a wide array of products, intermediates, or monomers through various transformations including hydrogenation, oxidation, reductive amination, etherification, and decarbonylation due to its diverse functional groups (hydroxy, aldehyde, furan ring). Particularly, diverse products can be derived from the hydrogenation of C=O, C=C, and C–OH, posing a significant challenge in developing active and highly selective catalysts. This minireview addresses recent developments in heterogeneous catalysts and their application to HMF hydrogenation. Emphasis is placed on hydrogenation pathways and the construction of catalytic systems. The aim is to provide researchers with a comprehensive understanding of hydrogenation, hydrogenolysis, and dehydrogenation reactions applicable to biomass conversion. Additionally, current challenges and future opportunities are outlined to guide further studies towards more efficient and scalable processes.

The exact determination of lactate concentration is very important in the fields of food quality and clinical diagnosis. A non-enzymatic amperometric sensor based on nanostructured porous Cu-Au electrocatalyst martial was designed and employed for lactate determination. For this purpose, the bimetallic surface was successfully coated on the glassy carbon electrode (GCE) using co-electrodeposition of copper and gold ions. The Cu-Au alloy proved to be an effective interface for the direct electrochemical oxidation of lactate. The Cu-Au modified GCE exhibits excellent lactate sensing capabilities thanks to the excellent conductivity of gold element in bimetallic material and high surface area of the porous Cu-Au alloy. In phosphate buffer solution, this novel electrochemical lactate sensor demonstrates a linear response to lactate within the concentration range of 20 to 2000 µM. The detection limit (based on S/N = 3) of the assay was estimated to be 5 µM. The established electrochemical sensing protocol is a highly selective device for the analysis of lactate in biological fluids. The lactate level in saliva samples was successfully quantified before and after exercise of athletes using the recommended strategy. The present non-enzymatic sensor offers a convenient, fast, cost-effective, and effective protocol for lactate measuring in clinical diagnosis applications.

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Bacteria indigenous to oil-contaminated water exhibited diverse metabolic capabilities in degrading various aromatic and monoaromatic hydrocarbons. Out of the 28 bacterial strains isolated from the wastewater, each was cultivated with at least one hydrocarbon, including kerosene, naphthalene, toluene, diesel, or aniline. Among these strains, Pseudomonas putida AD-128 emerged as one of the most effective polyaromatic hydrocarbon (PAH) degraders. Following a 6-day treatment period, strain P. putida AD-128 demonstrated proficiency in degrading various PAHs, including naphthalene, phenanthrene, and fluorine. After 6 days of incubation at 20 °C, the degradation of Naphthalene (NAP) notably increased. Gas Chromatography Mass Spectrometry analysis identified the degraded compounds, including pyruvic acid, salicylaldehyde, D-gluconic acid, and catechol. Optimal NAP degradation was observed at 20 °C and pH 6.0, with increased agitation speed correlating with enhanced bacterial growth and heightened degradation, particularly evident after 6 days at 20 °C. Peptone emerged as the most effective among the four nitrogen supplements (ammonium sulfate, potassium nitrate, beef extract, and peptone), significantly reducing residual naphthalene in the medium. The isolated indigenous bacterium, P. putida AD-128, exhibits robust capabilities in degrading PAHs under optimized conditions, making it a valuable asset for environmental management initiatives.

Water hyacinth (Eichhornia crassipes) as a aquatic weed has become a source of concern for value addition. This study aimed to determine the feasibility of the weedy biomass in sustainable bioethanol production using Phanerochaete chrysosporium and Saccharomyces cerevisiae. The results indicated that P. chrysosporium significantly utilized 70.9% of cellulose and 70% of hemicellulose from raw lignocellulose of water hyacinth with significant microbial enzyme production of 1.26 IU/ml. Moreover, the microbial treatment resulted in a significant amount of soluble protein (194.30 mg/g) and reducing sugar (34.20 g/l). XRD, SEM and FTIR analyses revealed that the crystalinity of cellulose was increased with the microbial treatment and hence, the yield of sugar also. Under submerged fermentation, Saccharomyces cerevisiae produced a maximum of 20.17 g/l of ethanol. The promising results of the present study explored the microbial treatment with P. chrysosporium and fermentation with S. cerevisiae as a successful and sustainable method for ethanol production from lignocellulosic weedy biomass.

In this paper, the CoxMn1Cey composite oxide catalyst was synthesized by the co-precipitation method. The structure–activity relationship of the catalyst was analyzed by characterization methods such as XRD, Raman, H₂-TPR, NH₃/NO_x-TPD, XPS, and in situ DRIFTS. The results showed that the Co3Mn1Ce1 catalyst resisted high space velocity, water, and sulfur. In addition, Ce doping could effectively increase the specific surface area of the catalyst. In a sulfur-containing atmosphere, Ce could preferentially react with SO₂ and act as a sacrifice site to protect the active components from toxicity. Co-doping greatly enhanced the redox capacity of the catalyst and increased the chemisorbed oxygen (O_S) content on the surface of catalysts. Co-presence of Co and Ce increased the content of surface-active Mn species, which further effectively improved the adsorption capacity of the catalyst for NH₃ and NO reactants. In situ DRIFTS results showed that the reaction on the Co3Mn1Ce1 catalyst followed both the Langmuir–Hinshelwood and Eley–Rideal mechanisms.

Hydrogen peroxide (H₂O₂) emerges as an environmentally sustainable oxidant with great potential in diverse fields. However, the efficiency of H₂O₂ generation via photocatalysis remains suboptimal. Fundamentally, this inefficiency stems from the rapid recombination of photogenerated electron–hole pairs, limited surface or interface activity, restricted solar light absorption, and poor selectivity. Here, we discuss the fundamental mechanisms of photocatalytic H₂O₂ generation over the key material systems and highlight the most effective design strategies to address the unmet challenges faced by these systems. This review not only discusses fundamental insights into the mechanisms of photocatalytic H₂O₂ generation but also provides perspectives on future directions for the development of photocatalytic materials with high-efficiency and stability in generating H₂O₂.

Insufficient infrastructure for wastewater treatment stands as a critical global concern, profoundly impacting both the environment and public health. This issue is exacerbated by industrial effluents containing hazardous organic pollutants and dyes such as crystal violet (CV) and methyl orange (MO), posing significant environmental threats. This study introduces a novel approach utilizing chitosan microsphere-based iron–strontium–zinc oxide photocatalysts aimed at addressing the decontamination of these organic dyes. The synthesis of iron–strontium–zinc oxide was performed via co-precipitation method followed by its characterization using various techniques. The resulting CS-Fe₂SrZnO₄ microspheres exhibited a sleek morphology with an average diameter of 917 μm, featuring the confirmed presence of iron, strontium, and zinc oxide as ascertained by EDX analysis. With a bandgap of 1.24 eV, this material showcased remarkable efficacy in degrading CV and MO dyes under solar light irradiation. Optimized conditions were identified to attain maximum degradation efficiency for both dyes. The findings reveal that the maximum degradation achieved for MO and CV was 94% and 98%, respectively, at the optimized conditions (time; 60 min, catalyst dosage; 0.1 g, concentration 20 ppm, pH; 6 for MO and 8 for CV). The statistical analysis was also performed which supported the obtained results. The kinetics study showed that the degradation followed pseudo-first order kinetics with R² value of 0.96. The current study has a great environmental impact as the degradation of hazardous dyes reduces the health related risks. To our best knowledge, this is the first report on the combination of ternary metal oxides combined with chitosan for the degradation of hazardous dyes.