Catalysis Surveys from Asia最新文献

This review discusses the synthesis, characterization, catalytic applications, mechanisms, current advances, challenges, and environmental consequences of Graphene oxide-based ferrite nanocomposites. The synthesis described the strategies used to synthesize these nanocomposites. The structural characterization was discussed using XRD, FTIR, and Raman spectroscopy techniques and how it could learn about their chemical composition and bonding. Morphological characterization said the results obtained on the nanostructure of these nanocomposites. The catalytic application phase is concerned with their use in photocatalysis, electrocatalysis, and magnetic catalysis, as well as the synergistic impact and the extra suitable electron switch pathways. The assessment also highlighted emerging developments in synthesis, novel catalytic applications, and capacity applications. The challenges and destiny directions discussed the importance of particular synthesis, management, balance, enhancement, and scalability. Compared to the sustainability, economic viability, and ecological effect, the environmental and monetary issues section underlined the significance of environmentally pleasant manufacturing and massive-scale viability.

The gas-phase carbonylation synthesis of Dimethyl carbonate (DMC) from carbon monoxide (CO) and methyl nitrite (MN) has the advantages of good availability of raw materials, high purity of DMC product, and no adverse impact on catalyst activity from the byproduct of water. The key to this method is to develop an efficient and stable carbonylation catalyst suitable for the reaction between CO and MN. The reaction mechanism and research progress of the catalysts are reviewed, including chlorine-containing system and chlorine-free system catalysts. The chlorine-containing system is mainly Wacker-type catalyst, and the research focus is how to avoid the loss of Cl^-. The chlorine-free system catalyst is mainly Pd/NaY zeolite catalyst, the challenge of this system catalyst is to stabilize the structure and chemical state of the active component to achieve high activity and selectivity. In the future, it is equally important to study the deactivation mechanism of the above-mentioned carbonyl catalysts.

Ionic liquids (ILs) have overcome solutions to problems associated with increased production with sustainable green approaches over the last three decades. Ionic liquids have appeared as a significant alternative to traditional organic solvents in metal-catalyzed reactions in organic synthesis. This substitution has proven to be instrumental in promoting sustainable development goals by facilitating an eco-friendlier approach to chemical synthesis. Carbon- carbon (C–C) cross-coupling reactions have a decisive role in organic and inorganic chemistry, acting as a flexible tool for the synthesis of complex molecules and materials. These reactions find their applications in various fields, including natural products, pharmaceuticals, and polymers. Among the most frequently used methods for C–C bond formation are the Heck and Suzuki reactions. In this review, we have examined and discussed the recent advancements in the use of ILs as solvents and catalysts in Heck and Suzuki reactions. We have explored various factors such as conversion, yield, catalyst recovery, and time reaction in the context of these reactions over the past few decades. The advantages and accomplishments of using ionic liquids have been evaluated with respect to their potential for enhancing the efficiency of industrial processes.

Cheese whey effluent (CWE) is a byproduct from cheese making industry having a high (50,000–100,000 mg/L) chemical oxygen demand (COD) which makes it mandatory to treat this effluent. Unlike the traditional methods known for CWE treatment – fermentation, enzymatic hydrolysis, ultrafiltration, etc., aqueous-phase reforming (APR) is a technology which helps to treat the wastewater by valorising it producing high heating value gases such as hydrogen (H₂), thus achieving a double benefit. In this work, APR of lactose as a model compound from CWE was carried out using a Pt promoted Ni/Htlc catalyst (where Htlc refers to hydrotalcite) in a stirred batch reactor. Experimental trials were performed where the reaction parameters viz. temperature (488–518 K), catalyst loading (2–6 kg/m³), reaction time (1.5–6 h) and lactose concentration (1–5 wt%) were optimized. For optimized parameters, H₂ selectivity of 73% was achieved. The catalyst support Htlc was prepared using Cu and Al, the former being water gas shift (WGS) promoter. Furthermore, the effect of promotion by Pt was investigated with three different loadings (1–5%), where 2.5% Pt outperformed others. The Ni loading was fixed at 10% in all the catalysts. The synthesized catalyst was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) analysis and Fourier transform infrared spectroscopy (FTIR). Finally, based on the experimental data, a rate law was proposed where the rate constant and adsorption constant of lactose were determined using multilinear regression. This work provides a proof-of-concept investigation for valorising CWE via APR using a novel catalyst Pt-Ni/Htlc.

The potential of Moringa Olivera biochar-modified Mg/Fe layered double hydroxides (LDHs) nanosheets as a sustainable adsorbent for removing naphthol green (NG) has been studied. Mg/Fe-LDH modified with Moringa biochar was created using in situ co-precipitation method. The synthetic LDHs were characterized using thermogravimetric analysis (TGA), field emission scan electron microscope (FE-SEM), transmission electron microscopy (TEM), energy-dispersive x-ray spectroscopy (EDS), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) techniques for nitrogen adsorption–desorption. Experimental design techniques are employed to optimize removal efficiency by examining factors such as pH, temperature, adsorbent dosage, and contact time. The resulting LDHs exhibits improved adsorption properties due to the combined effects of Mg/Fe LDHs and the high surface area of Moringa biochar (S_BET increased from 87 to 144 m²/g after modification with biochar). Through response surface methodology, optimal conditions are determined to maximize NG removal and found to be pH 7.8, contact time 150 min, dose 380 mg, and temperature 25°C. With an R² value of 0.999, 0.998 and an adjusted R² value of 0.997 and 0.993 in the RSM model for Mg/Fe and Mg/Fe-BC LDH, respectively, it can be concluded that the chosen model is appropriate for data analysis (quadratic model). Additionally, the adequacy precision was assessed using the signal-to-noise ratio, which was determined to be around 23 and 66 for Mg/Fe and Mg/Fe-BC LDH, respectively (significantly higher than the baseline of 4), indicating a satisfactory signal. The highest adsorption capacity of Mg/Fe and Mg/Fe-BC LDHs was determined to be 43 and 53 mg.g⁻¹ (with removal efficiencies of 82 and 97%, respectively). The Freundlich adsorption isotherm model testing characterized the removal of NG. A comprehensive kinetic study reveals a pseudo-first order. This study finds out the potential of Moringa biochar-modified Mg/Fe LDHs nanosheets as an effective green adsorbent for naphthol green removal in comparison with Mg/Fe free of biochar.

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The recent advances in the green-based design and synthesis of core-shell nanostructures have always been an intriguing arena to scientists due to their compelling application in catalytic fields. This work designed and synthesized a new core-shell nanosphere based on Fe₃O₄ as a novel, heterogeneous, reusable, efficient, and green catalyst to synthesize benzothiazole derivatives under ultrasonic irradiation. To achieve this goal, initially, fabricated Fe₃O₄ magnetic nanoparticles via the co-operation method were synthesized as a core, followed by coating with polyethylene glycol (PEG-400). Subsequently, Ni@Murexide complex supported on magnetic nanoparticles is successfully synthesized and reported, modified using 3-chloropropyltriethoxysilane (CPTES) and Murexide (MX) ligand in the Fe₃O₄@PEG support. The obtained structure of Fe₃O₄@PEG/MX/Ni was characterized by different analyses such as FT-IR, SEM, EDS, TEM, ICP-OES, XRD, VSM, and TGA. The results illustrated the effect of ultrasonic irradiation and the high efficacy of Murexide as a ligand in catalyzing the formation of benzothiazole derivatives and confirming the findings from the reaction of different derivatives of aromatic aldehyde with electron-withdrawing/donor groups with 2-amino thiophenol through a one-pot process in 10 min under ultrasonic irradiation which shows the non-sensitivity of the process to electronic effects. Furthermore, Fe₃O₄@PEG/MX@Ni showed great use at least six times with no significant loss in catalyst activity.

The present study is focused on the synthesis of zero-valent iron/cellulose acetate (Fe⁰-x/CA) membranes by phase inversion route for the activation of peroxymonosulfate (PMS). The generated ^•OH and SO₄^•− effectively degraded methylene blue (MB) dye in water to give comparatively non-toxic byproducts. The SEM investigations revealed that Fe⁰ nanoparticles are evenly dispersed into the CA membrane resulting in decline of agglomeration and enhancing the roughness of the composite surface. Moreover, the catalytic degradation of MB demonstrated that M5-alone showed 85% and was further boosted to 97% when coupled with PMS (M5/HSO₅⁻). The catalytic degradation of degradation of MB by M5/HSO₅⁻ membrane system in acidic, neutral, and basic media indicated that the degradation was 99.5%, 98.0%, 97.0%, 86.0% and 70.0% when the pH of the medium was 3, 5, 7, and 11, respectively. Furthermore, the degradation performance of M5/HSO₅⁻ membrane system was evaluated in de-ionized water (DIW), tape water (TPW) and industrial wastewater (IWW) and the results indicated that MB catalytic degradation was in the order of DIW (97%) > TPW (84%) > IWW (68%). Besides, various parameters like water flux permeability, contact angle, porosity, and fouling performance were also investigated. In addition, the degradation products were evaluated, and the degradation pathways were proposed accordingly.

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Hydrodeoxygenation (HDO) is a promising way to produce the second generation biodiesel from aliphatic acid based biomass. In this study, Ni_xMo_y@NC bimetallic catalysts with varying molar ratios were prepared using ZIF-8 as a representative MOF precursor. Lauric acid was chosen as the model compound, the catalytic performance of these catalysts with different metal ratios, reaction temperatures, and pressures was investigated. In addition, the reaction of lauric acid, lauric alcohol, and lauric aldehyde at different reaction times were investigated to explore the pathways of lauric acid. The influence of Mo doping on the catalyst structure, reducibility, and electronic properties was investigated through a series of characterizations, including SEM, TEM, XPS, H₂-TPR, and NH₃-TPD. This study revealed that the ZIF-8 support with incorporated Ni and Mo maintained a stable structure. Compared to Ni-based catalysts, the addition of Mo in the bimetallic catalyst can bring the electron transfer between Ni and Mo and increased the active sites and acid sites. An appropriate amount of Mo can lower the reduction temperature and enhance the catalytic activity for hydrogenation and deoxygenation reactions. Based on the catalytic experimental results, it can be observed that liquid alkanes, such as undecane and dodecane, are primarily formed through decarbonylation of lauric aldehyde and hydrodeoxygenation of lauric alcohol. Additionally, under high-temperature conditions, the hydrodeoxygenation reaction is favored over the decarbonylation reaction, promoting the production of dodecane. This indicates that Mo exhibits better activation for the C–OH reaction, leading to these observations. Under repeated use, the catalyst still has good catalytic activity and stability.

Zeolites (Hβ, HZSM-5 and HM), TiO₂ and ZrO₂ supported NiCo alloy catalysts were tested for the hydrodeoxygenation of phenol in aqueous phase. It has been found that the catalyst acidity remarkably influences the catalyst activity and the product distribution. Zeolites supported catalysts give much higher yield of the deoxygenated products (mainly benzene and cyclohexane) than NiCo/TiO₂ and NiCo/ZrO₂, where cyclohexanol and cyclohexanone are dominating. Associated with NH₃-TPD, we suggest that the catalyst acidity promotes the hydrodeoxygenation. Hβ zeolite supported NiCo alloy is more active than others, attributed to its higher metal dispersion and more acid sites. Therein, the Hβ zeolite calcined at 750 ^oC has moderate acidity, and its supported NiCo alloy catalyst (NiCo/HB-750) shows the best performance. Under a suitable reaction condition, the phenol conversion and the total yield of deoxygenated products reaches 96.8% and 94.5% on NiCo/HB-750, respectively.

Natural hematite supported cobalt (Co/Nat-Hem), a new heterogeneous catalyst, was successfully prepared by a simple impregnation technique. Textural, structural, functional groups and morphological aspects of the prepared catalyst were analyzed by BET, XRD, FT-IR, XRF, pH_pzc, SEM-EDX methods. BET analysis shows that the Co/Nat-Hem catalyst has a specific surface area of ​​13.44 m²/g and a pore volume of 0.062 cm³/g. The SEM-EDX method showed that 7.19 wt% of the cobalt species were dispersed on the surface of the prepared catalyst. The catalytic activity of Co/Nat-Hem was evaluated by photo-Fenton oxidation of the dye Cong red (CR). The effect of reaction parameters on CR oxidation efficiency was investigated. Under optimal reaction conditions (1 g/L catalyst concentration, 0.2 mol/L H₂O₂ initial concentration and pH 3), the percentage of CR discoloration reaches 97% after 30 min. The Co/Nat-Hem catalyst achieved a synergistic ratio of 28.5%, which was added to the oxidation rate of the Nat-Hem catalyst. The stability of the Co/Nat-Hem catalyst was demonstrated by the limited activity of leachates in the homogeneous Fenton oxidation of CR. The phytotoxicity of the CR dye was tested during the irrigation of the bean (Vicia faba L.).