Catalyst For Hydrolysis Research Articles

Photothermal catalytic hydrolysis of COS with enhanced efficiency over constructed alkali-modified La-Ti catalyst: Adjusting photogenerated electron behavior through metal‐support interactions

The low-temperature conversion of corrosive carbonyl sulfide (COS) in steel by-product gas is essential for the clean utilization of this gas. Herein, La-Ti@K catalysts doped with La nanoparticles were shown to exhibit significant photopromoted thermocatalytic activity and stability under UV light irradiation. At a reaction temperature of 60 °C, the TOF value increased from 4.84 × 10-4 s−1 (TiO2, thermal treatment) to 8.43 × 10-4 s−1 (La-Ti@K, photothermal treatment), and the H2S selectivity exceeded 99%. This was because La doping increased the density of basic sites on TiO2, which promoted the continuous dissociation of H2O in the system and the regeneration of –OH under UV irradiation. Moreover, the photogenerated electrons from TiO2 were transferred to La to maintain the metallic La nanoparticles, as well as to ensure the activation and photothermal hydrolysis of COS. The presence of a suitable electron-metal-support interaction (EMSI) between the electron-rich La nanoparticles and TiO2 might be responsible for these phenomena. In addition, theoretical calculations revealed that light-induced electron transfer was conducive to H2O dissociation and COS activation, while La doping reduced the free energy of the hydrolysis reaction. This work demonstrates the effectiveness of La-Ti@K catalyst in COS photothermal hydrolysis and provides a theoretical basis for further understanding of the photothermal catalytic mechanism.

Hydrothermally treated corncob as solid acid catalyst for facile hydrolysis of starch from avocado seed

Hydrothermally treated corncob as solid acid catalyst for facile hydrolysis of starch from avocado seed

Magnetically isolable Pd(0) nanoparticles supported on surface functionalized Fe3O4 for hydrogen generation via ammonia borane hydrolysis

AbstractPd(0) nanoparticles supported on surface functionalized magnetite (Fe3O4/SiO2‐NH2/HB@Pd) were prepared as catalyst for hydrolysis of ammonia borane (AB). The obtained magnetic nanocomposite material was seperated from the reaction media through a permanent magnet and characterized by FT‐IR, XRD, SEM‐EDX, TEM, ICP‐OES and XPS techniques. 100 mg Fe3O4/SiO2−NH2/HB@Pd nanocomposite with Pd metal content of 6.00±0.14 catalyzed the hydrolysis of 10 mM AB at 25 °C with 100 % yield. The presented work includes the effect of catalyst amount and temperature on the rate of the hydrolysis reaction of AB. As a result of the kinetic studies, the activation energy (Ea) for the Fe3O4/SiO2−NH2/HB@Pd catalyzed AB hydrolysis reaction was calculated as 34±1 kJ.mol−1, and the TOF value was calculated as 133 mol H2.(mol Pd(0).h)−1. The designed heterogenous magnetic nanocomposite catalyst demonstrated significant catalytic activity for AB hydrolysis reaction at 25 °C.

Regeneration of Co-based bead type catalyst in ammonia borane hydrolysis for hydrogen generation: Artificial neural networks and response surface methodology

The usage of ammonia borane (NH3BH3, AB) as a hydrogen storage medium and the release of hydrogen from its structure via hydrolysis has gained attention as for the hydrogen energy systems. Cobalt (Co)-based catalysts are the one of the activist material that can effectively catalyze the hydrogen production at current applications. However, Co-based catalysts have gradually lost their initial activities in long-term reactions due to by-product deposition on their surface. To address this issue, a catalyst regeneration strategy based on solvent washing to re-activation of Co-based catalysts with help of new perspective is presented in this study. Regeneration parameters as solution properties (pH:3–7), temperature (15–75 °C), and duration (10–50 min) have been modeled by both Response Surface Methodology (RSM) and Artificial Neural Network (ANN) techniques with different levels to optimize the process conditions for the regeneration process and to regain the high initial catalytic activity. The results have showed that solvent washing at optimization conditions was the effective method for restoring the activity of the catalyst. The findings indicate that time and temperature have a significant impact on the regeneration of the Co-based catalyst. The characterization techniques such as XRD, FTIR, HR-TEM, SEM/EDS, and XPS were performed to illuminate and correlate the effect of regeneration on the internal and external properties of fresh, used and regenerated catalysts. The optimum regeneration conditions, the pH of 6.5, the temperature of 44 °C, and the duration of 42 min under the optimal conditions identified by RSM, provided the highest hydrogen production (3.23 l min−1.g−1), showed much closer results to ANN technique predicted value (3.45 l min−1.g−1). It is shown that ANN has a relatively higher prediction accuracy and optimization ability compared to RSM for hydrogen production rate.

Facile “Green” synthesis of a novel Co–W–B catalyst from Rheum ribes shell extract and its effect on sodium borohydride hydrolysis: Kinetic mechanism

The present investigation aimed to assess the influence of the Co–W–B NPs catalyst on the process of sodium borohydride hydrolysis. The study involved the synthesis of Co–W–B NPs through the utilization of an eco-friendly green synthesis extract derived from the Rheum ribes shell in conjunction with the chemical reduction technique for catalyst production. The investigation of catalysts' structure and surface morphology was conducted through the utilization of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) techniques. The average particle size was determined to be 35 nm in TEM analysis. The presence of Co–W–B nanoparticles and their elemental composition % were determined through EDX analysis, revealing values of 63.9% (Co), 31.89% (C), 1.75% (B), and 2.46% (W) within the nanoparticle. The manufactured Co–W–B catalyst's use for hydrolysis of sodium borohydride was studied under various conditions, including different concentrations of NaOH and NaBH4, different amounts of catalyst, and different temperature parameters. The hydrogen production rate for the Co–W–B NPs catalyst in NaBH4 hydrolysis was determined to be 5367 mLg−1min−1 at 30 °C. The study involved the determination of TOF values for a catalyst composed of Co–W–B NPs, which were subjected to varying temperatures. The activation energies were determined through the utilization of the n-th order and Langmuir-Hinshelwood kinetic models and subsequently calculated using the Arrhenius equation, resulting in values of 35.36 and 31.70 kJ/mol, respectively. The values of enthalpy and entropy, ΔH and ΔS, were determined through the utilization of Eyring's equation, 18.49 kJ/mol and −80.7 J/mol.K, respectively.

Delignification of switchgrass for xylo-oligosaccharides production using sorbic acid hydrolysis

Organic acid as a class of hydrolysis catalysts shows great potential in the production of xylo-oligosaccharides (XOS) from lignocelluloses. However, sorbic acid (SA) hydrolysis for XOS production from lignocellulose has not been reported and it was still unclear how lignin removal affected XOS production. Herein, two factors affecting the XOS production from switchgrass by SA hydrolysis were explored: hydrolysis severity factor (Log R0) and lignin removal. Benefiting from the lignin removal (58.4%) in switchgrass, a desired XOS yield of 50.8% with low by-products was obtained from delignified switchgrass by 3% SA hydrolysis at Log R0 = 3.84. Under these conditions, 92.1% of glucose was obtained by cellulase hydrolysis with Tween 80 addition. From a mass balance perspective, 10.3 g of XOS and 23.7 g of glucose could be produced from 100 g switchgrass. This work proposed a novel strategy for XOS and monosaccharides production from delignified switchgrass.

Rattle-structured CuO/Co3O4@C microspheres, a potent bifunctional catalyst for hydrogen production from ammonia borane hydrolysis and methanolysis

Engineering and fabricating cost-effective and high-performing bifunctional catalysts for ammonia borane (AB) hydrolysis and methanolysis is paramount for their commercial availability. A series of rattle-structured CuO/Co3O4@C microsphere bifunctional catalysts for AB hydrolysis and methanolysis were produced using a simple hard template etching approach. The CuO/Co3O4@C-4 (4 refers to designed the mole ratio of Cu/Co) exhibits the best activity with TOF of 18.8 and 26.8 molH2·molcat-1·min−1 for AB hydrolysis and methanolysis, respectively. It is discovered that the excellent performance is mainly attributed to its unique rattle structure and the synergetic effect between Co3O4 and CuO. Kinetic isotope effect (KIE) experiments and infrared spectroscopy were applied to investigate AB hydrolysis and methanolysis reaction mechanisms. A suggested mechanism for AB methanolysis on rattle-structured CuO/Co3O4@C-4 is proposed based on the experiment results. This work could provide useful guidance for the construction of high-performance bifunctional catalysts for AB hydrolysis and methanolysis for hydrogen production.

Synthesis and catalytic performance of nanoflower-like Ru@CoAl-LDH composite catalyst for NaBH4 hydrolysis

Sodium borohydride (NaBH4) has been widely regarded as the one of most promising future hydrogen (H2)-generated materials. Therefore, it is necessary to find a catalyst with higher catalytic performance to promote the on-demand H2 release of NaBH4 hydrolysis. In this study, a [email protected] catalyst was developed by immobilizing Ru nanoparticles (Ru NPs) on the surface of Co Al Layered Double Hydroxide (CoAl-LDH) nanocurds. The Ru NPs were prepared by H2 reduction, and nanoflower-like CoAl-LDH was synthesized through a one-step solvothermal method. The microstructure and composition of the catalysts were investigated through scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results showed that [email protected] exhibited good catalytic performance toward the NaBH4 hydrolysis. At 30 °C, the hydrogen generation rate of the hydrolysis reaction was 44.34 L·min−1·gRu−1, and the reaction activation energy was 38.83 kJ·mol−1, and superior to many catalysts of the same type. Because of its high activity, low activation energy and excellent economic performance, this catalyst has high potential for applications in NaBH4 hydrolysis.

Copper-Doped NiCo2S4 Nanosheets Grown on Ni Foam Efficient Hydrogen Evolution Catalyst in Alkaline Solution

The development of economical, efficient and stable electrocatalysts for hydrogen evolution reaction (HER) with non-precious metals remains challenging. In this work, we have prepared Cu-doped NiCo2S4 nanosheets grown on nickel foam that can serve as excellent electrocatalysts for HER in alkaline solutions (Cu-NiCo2S4/NF). The good electrocatalytic properties and excellent stability of the pristine NiCo2S4 were achieved by changing its morphology through a simple Cu doping strategy. The optimum doping ratio for the Cu-NiCo2S4/NF catalyst in the HER requires an overpotential of only 155 mV to achieve a current density of 10 mA cm−2 and can operate stably for at least 12 h. This is mainly due to the fact that the doping of copper optimizes the electronic structure of the NiCo2S4/NF surface, providing more catalytically active sites and thus facilitating the effective release of hydrogen. In addition, the electrocatalytic activity of the Cu-NiCo2S4/NF material exceeds that of most reported noble metal-free catalysts, which also provides a new strategy for the preparation of NiCo2S4-based hydrolysis catalysts.

Influence of Excipients and Pressing Force on the Impurity Content of N-(4-aminobenzoyl)-L-glutamic Acid in Folic Acid Drugs During Storage

Introduction. Excipients, impurities contained in them, and sorbed water are one of the reasons for degradation of the active pharmaceutical substance (API). Excipients effect should be especially evaluated for moisture-sensitive APIs. Folic acid (FA) is an important vitamin for humans. It hydrolyze in water under the action of UV irradiation and main decomposition product is N-(p-aminobenzoyl)glutamic acid (impurity A). We found an increase in the content of impurity A during FA film-coated tablets storage in PVC-film and aluminum foil packaging in the absence of UV irradiation.Aim. Investigate the effect of excipients and parameters of the production process on the content of impurity A during storage of FA drugs.Materials and methods. The FA tablets containing 1.0 mg of API produced by direct compression technology were the objects of study. The pressing force (PF) was varied from 5 to 15 kN.Results and discussion. We found that content of impurity A in tablets containing 93.0 % lactose monohydrate and obtained with PF above 10 kN exceeded limit value during storage for 300 days. Probably lactose simultaneously acts both as a source of free water and as a catalyst for FA hydrolysis. Since the interaction of lactose and FA occurs in the solid phase, pressing accelerates hydrolysis by increasing the contact area of substances and the mobility of water molecules.Conclusion. We found that lactose monohydrate probably is the main cause of FA hydrolysis in drugs. Independently of the mechanism of its action, an increase in the PF above 10 kN leads to an increase in the rate of FA hydrolysis. This is due to an increase in the mobility of water molecules and the contact area between the excipient and API. We have selected the optimum pressure range (5–10 kN) for tablet mix containing lactose monohydrate and FA.

Hydrolysis of High Concentration Sucrose Solution into Glucose and Fructose over Amberlyst-15 Catalyst

This study aimed to investigate the effects of the reaction time and temperature on the hydrolysis of sucrose to glucose and fructose using an Amberlyst-15 catalyst. The experiments were conducted in a 100 mL high-pressure batch reactor. The initial sucrose concentration of 500 g/L, initial nitrogen pressure of 101.3 kPa, and catalyst loading of 0.2 g remained constant during the reactions. An increase in the reaction temperature and time, which varied in the range of 303–373 K and 1–12 h, respectively, resulted in an increase in the glucose and fructose yields owing to the high acidity of Amberlyst-15. The most elevated glucose and fructose yields based on carbon moles of 0.50 mol-C/mol-C and 0.49 mol-C/mol-C, respectively, were obtained at 373 K after 3 h with complete sucrose conversion. Moreover, Amberlyst-15 was reused for more than 24 cycles, with complete sucrose conversion and a high yield of inverted sugar. Therefore, Amberlyst-15 is an active, selective, and stable catalyst for sucrose hydrolysis.

Co/Fe3O4@GO catalyst for one-step hydrogen generation from hydrolysis of NaBH4: Optimization and kinetic study

In this study, cobalt nanocatalysts supported on the Fe3O4@GO were synthesized for boosting hydrogen generation upon hydrolysis of sodium borohydride. Co/Fe3O4@GO catalysts were synthesized through a facile co-precipitation method followed by a chemical reduction step. The prepared samples were characterized using various techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), Vibrating sample magnetometer (VSM), and Nitrogen adsorption–desorption (BET). Benefiting from the high crystallinity, good dispersion of Co nanoparticles over the Fe3O4@GO, and the synergistic effect between Co nanoparticles and Fe3O4@GO support, Co/Fe3O4@GO catalysts with 30 wt% cobalt loading showed the highest catalytic activity with high hydrogen generation rate of 4000 mL/min.gcat and relatively good stability. To investigate the effect of the parameters on hydrogen generation rate and optimal reaction conditions, the Box-Behnken design under response surface methodology (RSM) was applied. ANOVA results denoted that the temperature with the highest F-value and lowest P-value had the most effect on the hydrogen generation rate. Under the optimum conditions including a temperature of 39.83 °C, 17.74 mg of catalyst, and 5.135 wt% NaBH4 concentration, Co(30%)/Fe3O4@GO exhibited a superior H2 generation rate of 6005 mL/min.gcat and low activation energy of 44.4 kJ/mol. Therefore, the Co/Fe3O4@GO is a promising catalyst for NaBH4 hydrolysis due to its easy preparation and separation method, high hydrogen generation rate, and low activation energy.

High entropy alloy nanoparticles as efficient catalysts for alkaline overall seawater splitting and Zn-air batteries

High entropy alloys (HEAs) are those metallic materials that consist of five or more elements. Compared with conventional alloys, they have much more catalytic active sites due to unique structural characteristics such as high entropy effect and lattice distortion, endowing them with promising applications in the region of hydrolysis catalysts. Herein, we successfully loaded high-entropy alloys onto carbon nanotubes (FeNiCoMnRu@CNT) by hydrothermal means. It exhibits excellent HER and OER properties in alkaline seawater. To accomplish two-electrode total water splitting when constructed into Zn air cells, it only needed 1.6 V, and the timing voltage curve showed a steady current density of 10 mA cm−2 during constant electrolysis for more than 30 h in alkaline seawater. The remarkably high HER and OER activity of FeNiCoMnRu@CNT HEAs NPS indicates the potentially broad application prospect of HEAs for Zn air battery.

Hierarchical Porous NiCo/HZIF-8 Catalyst for Highly Efficient Hydrogen Generation from Sodium Borohydride Hydrolysis

Designing an efficient catalyst for NaBH4 hydrolysis remains challenging. In this work, the Ni-Co nanocatalyst supported by the zeolitic imidazolate framework (NiCo/HZIF-8) was successfully prepared by an impregnation–chemical reduction method. The microstructure, catalytic activity, and durability of the nanocatalyst were investigated. The as-prepared NiCo/HZIF-8 nanocatalyst shows a hierarchical porous structure with high specific surface area and good dispersion for the metal nanoparticles (MNPs), which is beneficial to exposing active sites and promoting catalytic performance. The activation energy (Ea) for the hydrolysis of NaBH4 catalyzed by NiCo/HZIF-8 is as low as 32.01 kJ·mol–1, and the maximum turnover frequency (TOF) is 41,254 mLH2 · gM–1 · min–1, surpassing the performance of numerous non-noble metals and even some noble metal nanocatalysts. In addition, the NiCo/HZIF-8 nanocatalyst can retain 85.5% of its initial catalytic activity for NaBH4 hydrolysis after five cycles.

Enhancing Kinetics of Carbonyl Sulfide Hydrolysis Using Pt-Supported Al2O3 Catalysts: First-Principles-Informed Energetic Span Analysis

Catalytic hydrolysis is considered an effective strategy for treating carbonyl sulfide (COS)─a toxic sulfur-containing gas that causes problems to the environment and petrochemical industries. Al2O3-based materials are commonly used as catalysts for COS hydrolysis owing to their stability and cost effectiveness. However, they still suffer from sulfur poisoning leading to partial COS conversion after long time use. To improve their catalytic performances, herein, we computationally designed and studied the catalytic activity of the Pt-supported Al2O3 catalysts by means of density functional calculations. We mechanistically explored the COS hydrolysis on both bare and Pt-decorated surfaces to reveal the role of Pt catalysts in the reaction kinetics. We find that bare Al2O3 suffers from difficult C–S bond breaking as its barrier is relatively high. Pt facilitates C–S bond breaking where its barrier is reduced by more than half (1.34 to 0.60 eV). However, the Pt–Al2O3 catalyst could encounter sulfur poisoning as the sulfur-containing intermediates are rather stable. Such issues could be remedied by increasing the operating temperature to destabilize the intermediates and promote product desorption. The energetic span models reveal that the important states of bare and Pt–Al2O3 are indeed C–S bond breaking and product desorption corresponding to an energy span of 2.72 and 1.67 eV at 773 K, respectively─suggesting that Pt dramatically enhances the catalytic activity of Al2O3-based catalysts toward COS hydrolysis. The suggested operating temperatures are above 673 K to avoid sulfur poisoning. Our findings will be useful for the development of more efficient Al2O3-based catalysts for treating COS.

New Trends and Perspectives in Production of 1,2-Propanediol

The production of 1,2-propanediol is a significant challenge for the chemical industry due to the increasing demand for this versatile product and the pro-ecological regulatory actions. The traditional method of producing this compound through the hydrolysis of petroleum-derived 1,2-epoxypropane (propylene oxide) is energy intensive, and sustainable routes based on renewable raw materials are becoming more attractive. This perspective presents the current state of scientific and patent literature on the production of 1,2-propanediol and the implementation of new technologies by leading companies. This perspective also discusses alternative pathways, including glycerol hydrogenolysis and biotechnological methods, highlighting their potential to reduce energy consumption and lower the carbon footprint of the process. The focus is on modern methods, including chromium-free catalytic systems for glycerol hydrogenolysis, in situ hydrogen generation, and multifunctional catalysts for saccharides hydrolysis and hydrogenolysis. Biobased 1,2-propanediol produced from renewable alternative raw materials has great potential to replace traditional petroleum-derived 1,2-propanediol with substantial environmental and economic benefits.

Hydrolysis of nitrile catalyzed by a tripalladium complex

Metal cluster catalysis is a topic that has attracted much attention because clusters can be superior catalysts than homogeneous ones. A tripalladium complex Pd3, supported by a multiple dentate 2,7-di(pyridin-2-yl)-1,8-naphthyridine is a good catalyst for hydrolysis of nitrile into the corresponding amides under mild and neutral conditions. Typically, 3-methoxypropanenitrile was hydrolyzed into 3-methoxypropanamide quantitatively with the use of Pd3 (1 mol%) and AgBF4 as the catalyst in water/THF at 50 °C for 16 h.

M-BDC (M = Co and/ or Fe) MOFs as effective catalysts for hydrogen generation via hydrolysis of sodium borohydride

Mono- (Co-BDC, Fe-BDC) and bimetallic FeCo-BDC Metal-Organic Frameworks are successfully synthesized by the solvothermal method in DMF at 150 °C within 15 h and tested as catalysts for sodium borohydride hydrolysis. The materials are characterized by FTIR, PXRD, TGA, ICP-OES, H2-TPR, BET model, and SEM-EDS. The catalytic activity of these materials is studied for dehydrogenation of sodium borohydride in water at various temperatures under basic conditions. Among tested catalysts, the most promising is Co-BDC, which provides hydrogen generation with a good rate of 1886.8 mL min−1 gcat−1 at 319 K and high efficiency (77.7 %) in the presence of a base. The activation energy determined as 25.4 kJ mol−1 is lower than most cobalt-bearing catalysts for NaBH4 hydrolysis described in the literature. The catalyst can be reused at least ten times, keeping a good overall hydrogen generation yield, and thus can be considered a promising candidate for portable hydrogen fuel systems.

Recent Advances and Perspectives on Supported Catalysts for Heterogeneous Hydrogen Production from Ammonia Borane.

Ammonia borane (AB), a liquid hydrogen storage material, has attracted increasing attention for hydrogen utilization because of its high hydrogen content. However, the slow kinetics of AB hydrolysis and the indefinite catalytic mechanism remain significant problems for its large-scale practical application. Thus, the development of efficient AB hydrolysis catalysts and the determination of their catalytic mechanisms are significant and urgent. A summary of the preparation process and structural characteristics of various supported catalysts is presented in this paper, including graphite, metal-organic frameworks (MOFs), metal oxides, carbon nitride (CN), molybdenum carbide (MoC), carbon nanotubes (CNTs), boron nitride (h-BN), zeolites, carbon dots (CDs), and metal carbide and nitride (MXene). In addition, the relationship between the electronic structure and catalytic performance is discussed to ascertain the actual active sites in the catalytic process. The mechanism of AB hydrolysis catalysis is systematically discussed, and possible catalytic paths are summarized to provide theoretical considerations for the designing of efficient AB hydrolysis catalysts. Furthermore, three methods for stimulating AB from dehydrogenation by-products and the design of possible hydrogen product-regeneration systems are summarized. Finally, the remaining challenges and future research directions for the effective development of AB catalysts are discussed.

Synthesis of cobalt-doped catalyst for NaBH4 hydrolysis using eggshell biowaste

In the present study, a cobalt-doped catalyst was prepared from chicken eggshell powder (CEP) biowaste to be used in the hydrolysis of sodium borohydride (NaBH4). In the presence of the prepared catalyst (CEPcat), possible effects of the parameters of NaOH concentration (%), catalyst amount (g), NaBH4 concentration (%), process temperature (oC) and reusability affecting the hydrolysis of sodium borohydride were examined. The CEPcat obtained was characterized with FT-IR, TGA, XRD, SEM and EDX analyses. The hydrogen generation rate (HGR) was determined as 432 mL gCo−1 min−1 in the presence of 1 g CEPcat, a CoO/CaO ratio of 10/90 and 1% NaBH4 concentration. The activation energy of the NaBH4 hydrolysis reaction was calculated as 16.78 kJ mol−1. After 16 reuses of the CEPcat there was no significant decrease in the hydrogen volume. Compared to the first use while there was an increase in the HGR. These results showed that the CEPcat prepared has a significant advantage over other catalysts for use in NaBH4 hydrolysis.