CWPO of 4-CP and industrial wastewater with Al–Fe pillared clays

2010 ◽  
Vol 61 (8) ◽  
pp. 2161-2168 ◽  
Author(s):  
C. B. Molina ◽  
J. A. Zazo ◽  
J. A. Casas ◽  
J. J. Rodriguez
Keyword(s):  
Catalytic Activity ◽  
Industrial Wastewater ◽  
Active Phase ◽  
Pillared Clays ◽  
Stoichiometric Ratio ◽  
Experimental Conditions ◽  
Compound A ◽  
Wet Peroxide Oxidation ◽  
Lower Temperature ◽  
Pillaring Solution

Catalysts based on pillared clays with Al–Fe have been synthesised from a commercial bentonite and tested for catalytic wet peroxide oxidation (CWPO) of aqueous 4-Chlorophenol (4-CP) solution and industrial wastewater from cosmetics manufacture. The effect of the synthesis procedure, the iron load and reaction temperature on the catalytic activity was studied using 4-CP as target compound. A lower temperature in the preparation of the pillaring solution, as well as a higher Fe load, gave rise to a higher catalytic activity, but also a higher leaching of the active phase. The best catalyst, in terms of catalytic activity, was also tested for treating cosmetic wastewater by CWPO. Experiments were carried out at 90°C and atmospheric pressure and the influence of Fe load, catalyst concentration and H2O2/COD ratio (between 0.5 and 2 times the stoichiometric ratio) were analysed. Higher values of these parameters favour COD reduction. The Fe leaching in all cases was lower than 1.2 mg/L, indicating that these catalysts have a high stability under these experimental conditions.

scholarly journals Role of CO2 During Oxidative Dehydrogenation of Propane Over Bulk and Activated-Carbon Supported Cerium and Vanadium Based Catalysts

2021 ◽  
Author(s):  
Petar Djinović ◽  
Janez Zavašnik ◽  
Janvit Teržan ◽  
Ivan Jerman
Keyword(s):  
Catalytic Activity ◽  
Activated Carbon ◽  
Oxidative Dehydrogenation ◽  
Active Phase ◽  
Lattice Oxygen ◽  
Chemisorbed Oxygen ◽  
Catalytically Active ◽  
Temperature Programmed ◽  
Propane Cracking

AbstractCeO2, V2O5 and CeVO4 were synthesised as bulk oxides, or deposited over activated carbon, characterized by XRD, HRTEM, CO2-TPO, C3H8-TPR, DRIFTS and Raman techniques and tested in propane oxidative dehydrogenation using CO2. Complete oxidation of propane to CO and CO2 is favoured by lattice oxygen of CeO2. The temperature programmed experiments show the ~ 4 nm AC supported CeO2 crystallites become more susceptible to reduction by propane, but less prone to re-oxidation with CO2 compared to bulk CeO2. Catalytic activity of CeVO4/AC catalysts requires a 1–2 nm amorphous CeVO4 layer. During reaction, the amorphous CeVO4 layer crystallises and several atomic layers of carbon cover the CeVO4 surface, resulting in deactivation. During reaction, V2O5 is irreversibly reduced to V2O3. The lattice oxygen in bulk V2O5 favours catalytic activity and propene selectivity. Bulk V2O3 promotes only propane cracking with no propene selectivity. In VOx/AC materials, vanadium carbide is the catalytically active phase. Propane dehydrogenation over VC proceeds via chemisorbed oxygen species originating from the dissociated CO2. Graphic Abstract

scholarly journals Tailoring of Hydrotalcite-Derived Cu-Based Catalysts for CO2 Hydrogenation to Methanol

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1058 ◽  
Author(s):  
Leone Frusteri ◽  
Catia Cannilla ◽  
Serena Todaro ◽  
Francesco Frusteri ◽  
Giuseppe Bonura
Keyword(s):  
Metallic Copper ◽  
Chemical Properties ◽  
Active Phase ◽  
Co2 Hydrogenation ◽  
High Dispersion ◽  
Experimental Conditions ◽  
Typical Structure ◽  
Methanol Production ◽  
Physico Chemical ◽  
Space Time Yield

Ternary CuxZnyAlz catalysts were prepared using the hydrotalcite (HT) method. The influence of the atomic x:y:z ratio on the physico-chemical and catalytic properties under CO2 hydrogenation conditions was probed. The characterization data of the investigated catalysts were obtained by XRF, XRD, BET, TPR, CO2-TPD, N2O chemisorption, SEM, and TEM techniques. In the “dried” catalyst, the typical structure of a hydrotalcite phase was observed. Although the calcination and subsequent reduction treatments determined a clear loss of the hydrotalcite structure, the pristine phase addressed the achievement of peculiar physico-chemical properties, also affecting the catalytic activity. Textural and surface effects induced by the zinc concentration conferred a very interesting catalyst performance, with a methanol space time yield (STY) higher than that of commercial systems operated under the same experimental conditions. The peculiar behavior of the hydrotalcite-like samples was related to a high dispersion of the active phase, with metallic copper sites homogeneously distributed among the oxide species, thereby ensuring a suitable activation of H2 and CO2 reactants for a superior methanol production.

Numerical Simulation of Impinging Cooling on the Leading Edge of a Turbine Blade

2011 ◽  
Author(s):  
Keyong Cheng ◽  
Xiulan Huai ◽  
Jun Cai ◽  
Zhixiong Guo
Keyword(s):  
Numerical Simulation ◽  
Turbine Blade ◽  
Leading Edge ◽  
Critical Factor ◽  
Main Stream ◽  
Experimental Conditions ◽  
Cooling Effectiveness ◽  
Blowing Ratio ◽  
Lower Temperature ◽  
Simulation Parameters

In the present study, numerical simulation is carried out for impingement/effusion cooling on the leading edge of a turbine blade similar to an experimental model tested previously. The k-ε turbulence model is used, and simulation parameters are set in accordance with the experimental conditions, including temperature ratio, blowing ratio, and Reynolds number of the main stream. The accuracy and reliability of the simulation is verified by the experimental data, and the influence of various factors on fluid flow and heat transfer is analyzed in detail. The results indicate that the blowing ratio is one critical factor which affects the cooling effectiveness. The greater the blowing ratio is, the higher the cooling effectiveness is. In addition, a staggered-holes arrangement is numerically studied and compared with a line-holes arrangement. The results show that the staggered-holes arrangement has a lower temperature on the outer surface of the leading edge and has improved the cooling effectiveness.

Selective oxidation of propene to acrolein on FeMoTeO catalysts: determination of active phase and enhancement of catalytic activity and stability

2017 ◽  
Vol 7 (20) ◽  
pp. 4629-4639 ◽  
Author(s):  
M. Tonelli ◽  
M. Aouine ◽  
L. Massin ◽  
V. Belliere Baca ◽  
J. M. M. Millet
Keyword(s):  
Catalytic Activity ◽  
Selective Oxidation ◽  
Active Phase ◽  
Propene Oxidation

Multicomponent FeMoTeO catalysts have been synthesized and studied for mild propene oxidation to acrolein.

Trimetallic RuxMoNi Catalysts Supported on SBA-15 for the Hydrodesulfurization of Dibenzothiophene

2018 ◽  
Vol 17 (5) ◽  
Author(s):  
N.L. Torres-García ◽  
R. Huirache-Acuña ◽  
T.A. Zepeda-Partida ◽  
B. Pawelec ◽  
J.L.G. Fierro ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Catalytic Activity ◽  
Chelating Agent ◽  
Active Phase ◽  
Atomic Ratio ◽  
Support Interaction ◽  
Micro Raman Spectroscopy ◽  
Metal Support Interaction ◽  
Sulfided Catalysts ◽  
Metal Support

Abstract In this work, novel trimetallic catalysts based on transition metal sulphides (Ru, Mo and Ni) supported on SBA-15 were synthesized. Citric acid (CA) was used as chelating agent in order to enhance the dispersion of the active phase and minimize the metal-support interaction. Sulfided catalysts were evaluated in the reaction of hydrodesulfurization (HDS) of dibenzothiophene (DBT) at 320 °C and 54.5 atm of total H2 pressure. The effects of different Ru/(Ni + Mo) atomic ratios on the active phase were studied. The catalysts were characterized using Micro-Raman spectroscopy, DRIFTS, XRD, XPS, HR-TEM and SEM techniques. Results have shown that there was a better dispersion of the metallic phases, which improves the physicochemical properties of the catalysts, increasing the catalytic activity. The trimetallic RuxMoNi catalyst with the lowest atomic ratio, have shown superior catalytic activity compared to their higher atomic ratio counterparts. The interaction of the chelating agent improved the catalytic activity, which was superior to that observed for NiMo based catalysts, considered one of the most active hydrotreating catalysts.

Ru/TiO2 Nanostructured Catalysts: Synthesis, Characterization and Catalytic Activity Towards Hydrogenation of Ethyl Levulinate

2021 ◽  
Vol 21 (12) ◽  
pp. 6160-6167
Author(s):  
Sakthivel Kumaravel ◽  
Sivakumar Thiripuranthagan ◽  
Elangovan Erusappan ◽  
Aishwarya Sivakumar ◽  
Saranraj Kumaravel ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Inductively Coupled Plasma ◽  
Sol Gel ◽  
Nanostructured Catalysts ◽  
Optical Emission ◽  
Morphological Properties ◽  
Emission Spectrometry ◽  
Experimental Conditions ◽  
Ethyl Levulinate ◽  
Ru Nanoparticles

Pristine TiO2 and x% Ru/TiO2 catalysts with different wt.% of Ru (x%= 1.5%, 2%, 2.5% and 3%) were synthesized using sol–gel and simple impregnation methods. Different characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), High-resolution transmission electron microscope (HR-TEM), Inductively coupled plasma-optical emission spectrometry (ICP-OES) and Thermogravimetry/Differential thermal analysis (TG/DTA) were used to study the physicochemical and morphological properties. The XRD patterns of the as-prepared pristine TiO2 catalyst showed high crystalline nature. The HR-TEM images revealed that the Ru nanoparticles (NPs) were evenly dispersed on the TiO2 surface. The prepared catalysts were evaluated for their catalytic activity towards the liquid phase hydrogenation of ethyl levulinate under mild reaction conditions (ambient H2 pressure). Among the various catalysts, 2.5% Ru/TiO2 catalyst showed the maximum catalytic activity of 79% ethyl levulinate (EL) conversion with 82% selectivity of γ-valerolactone (GVL). The recyclability test revealed that the most active 2.5% Ru/TiO2 also showed the highest stability of the catalyst under optimized experimental conditions.

A Cost-Effective 3D Hydrogen Evolution Cathode with High Catalytic Activity: FeP Nanowire Array as the Active Phase

2014 ◽  
Vol 53 (47) ◽  
pp. 12855-12859 ◽  
Author(s):  
Ping Jiang ◽  
Qian Liu ◽  
Yanhui Liang ◽  
Jingqi Tian ◽  
Abdullah M. Asiri ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Nanowire Array ◽  
Cost Effective ◽  
Active Phase ◽  
High Catalytic Activity
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