Synthesis and characterization of vanadium pentoxide on different metal oxides by the sol-gel process for application in the conversion of the SO2 to SO3

Sulfuric acid is the largest volume chemical currently produced in the world. Is manufactured by the contact process, it involves three stages: combustion, conversion and absorption. The SO2 conversion reaction is the key step in the process, it uses catalysis. The objective of this work is to synthesize a series of mixed vanadium oxides X% / MO2 with M (Si, Al and Ti) by sol-gel process followed by calcination at 400 ° C, in order to study their reactivity in the catalytic oxidation of SO2 to SO3. Characterization of those materials was carried out by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), X-ray diffraction, thermal analysis (TDA/TGA) and N2 adsorption at 77 K. Their acid-base properties are studied by the decomposition reaction of isopropanol (propan-2-ol). In this work, we have studied the reactivity of the catalysts prepared in the conversion of SO2 to SO3 by an iodometric as dosage which consists in assaying the iode with sodium thiosulfate

Removal of cationic dye by high surface activated carbon prepared from biomass (date pits) by carbonization and activation processes

In this work,we investigated the capacity of activated carbon (AC) to adsorb Methylene Blue (MB) from aqueous solution. AC-H3PO4 and AC-ZnCl2was obtained from date pits via a one-step chemical method using H3PO4 and ZnCl2 as activating agents. The performance of AC was characterized by different analyses techniques: proximate analysis, SEM, XRD and FT- IR and TGA. The experiments results showed that the MB removal increased by increasing each of AC-H3PO4 and AC-ZnCl2 concentration, contact time and temperature. The efficiency of the adsorption tests are evaluated by the Langmuir and Freundlich isotherm models. Equilibrium data fitted well by Freundlich modelwith a maximum of the adsorption capacity of 95 mg/g at 333 K for AC-ZnCl2, However, the adsorption was well adapted to the Langmuir isotherm with a maximum of the adsorption capacity of 125 mg/g at 298 K for AC-H3PO4. The kinetics data was explained by the pseudo second-order model, and the intra-particle diffusion with some other rate controlling steps has been suggested as the adsorption mechanism. The pseudo-second-order model described better the adsorption process. The thermodynamic study suggested that MB adsorption on AC-ZnCl2 was endothermic, spontaneous and non-spontaneous for AC-H3PO4.         

Thermodynamic properties of 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole as corrosion inhibitor of carbon steel in hydrochloric acid pickling environment

The corrosion inhibition of carbon steel in 1 M HCl by 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole (DAPO) was investigated using weight loss method in the temperature range of 303–333 K. It was found that the inhibition efficiency increases with an increase in DAPO concentration but decreases with an increase in temperature. It has been determined that the adsorption for the studied inhibitor on carbon steel complies with the Langmuir adsorption isotherm at all studied temperatures. Both kinetic parameters (activation energy, pre-exponential factor, enthalpy of activation and entropy of activation) and thermodynamics of adsorption (enthalpy of adsorption, entropy of adsorption and Gibbs free energy) were calculated and discussed

Inhibitive effect of some phosphonate derivatives on the corrosion of carbon steel in 2 M H3PO4

Corrosion inhibition performance of some phosphonate derivatives, namely, dodecylphosphonic acid (YM1),  sodium methyl dodecylphosphonate (YM2) and methyl hydrogen dodecylphosphonate (YM3)  on carbon steel in 2 M H3PO4 solution was investigated by means of weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. These compounds inhibit the corrosion rate even at very low concentrations and the order of increasing inhibition efficiency was correlated with the modification of the molecular structure of the inhibitors. Polarization curves indicated that these compounds acted primarily as mixed-type inhibitors. The adsorption of these compounds on carbon steel surface has been found to obey Langmuir’s adsorption isotherm. E% values obtained from weight-loss and electrochemical methods were in good agreement. size:12.0pt;line-height:200%;font-family:"Times New Roman","serif"; color:black'>.

Potential Anticorrosive Effect of Hexamethylenediamine Penta(methylphosphonic) Acid on Carbon Steel in Hydrochloric Acid Solution

The inhibition ability of Hexamethylenediamine penta(methylphosphonic) acid (HTMP) against carbon steel corrosion in 1 M HCl at 30°C was evaluated by weight loss, electrochemical (potentiodynamic and electrochemical impedance spectroscopy, EIS) methods. The experimental results showed that HTMP was a good inhibitor for the steel corrosion in 1 M HCl medium and its inhibition efficiency increased with the inhibitor concentration. Data, obtained from ac impedance measurements, were analyzed to model the corrosion inhibition process through appropriate equivalent circuit models. Adsorption of HTMP on the carbon steel surface followed the Langmuir adsorption isotherm. Surface analysis by (SEM) supported the formation of a protective inhibitor film on the carbon steel surface. Furthermore, the theoretical study was carried out using the density functional theory (DFT) metho

Corrosion Inhibition on Mild Steel by Phosphonium Salts in 1M HNO3 Aqueous Medium

The corrosion inhibition on mild steel by phosphonium salts in 1 M HNO3 medium has been investigated by weight loss and polarization techniques. The result revealed that these derivatives are excellent inhibitors. Potentiostatic polarization, impedance and electrochemical noise studies showed mixed type inhibitors. Ellipsometer, quantum chemical and FTIR results indicated Phosphonium bromide derivatives exhibit excellent corrosion protective thin layer performance

Electrochemical Oxidation Assessment and Interaction of 2-aminoethanol and N, N-diethylethanamine Propagation in Acidic Medium

Electro�oxidation and inhibitor performance of copper specimens in 1 M hydrochloric acid solu� tion was investigated at room temperature by linear potentiodynamic polarization and gravimetric method in the presence of 2�aminoethanol (A) and N, N�diethylethanamine (D) as an inorganic inhibitor. The effect of the inhibitory concentration on the corrosion behavior of copper was studied over 288 hrs at 298°K. The inhibitory efficiency rise up to 96% for single induced and 98% for synergistic behavior. The adsorption mechanism characteristic was supported by SEM/EDX analysis and adsorption isotherm. From all indica� tion, the inhibitive efficiency of these compounds majorly depends on their molecular structure and concen� tration. The blocking effects of the surface interface were also explained on the basis of the inhibitor active action. 2�aminoethanol and N, N�diethylethanamine inhibits copper in 1 M HCl by strictly affecting both the anodic and cathodic sites. Portion of the surface covered calculated was also found to follow Langmuir adsorption isotherm