Sharif Digital Repository

Coke deposition mechanism on a commercial Pt-Re/γ-Al 2O3 naphtha reforming catalyst was studied. A used catalyst that was in industrial reforming operation for 28 months, as well as the fresh catalyst of the unit were characterized using XRD, XRF, and nitrogen adsorption/desorption analyses. Carbon and sulfur contents of the fresh and the used catalysts were determined using Leco combustion analyzer. The pore size distributions (PSD) of the fresh and the used reforming catalysts were determined using BJH and Comparison Plot methods. The Comparison Plot method produced the most reasonable PSDs for the catalysts. Through comparison of the PSDs of the fresh and the used catalysts, it was... 

Two-dimensional mesoporous carbon nitride and its highly efficient nanorod framework were prepared via hard-templating method. The obtained materials were fully characterized. The results showed that the samples structural ordering and morphology were similar to those of the parent silica templates; they had large pore volumes as well as high surface area structures. Carbon nitride carbocatalysts were used for H2S selective oxidation. The catalytic tests were carried out at 190, 210 and 230 °C in a fixed bed reactor. The obtained selectivity values for mesoporous carbon nitride rod and mesoporous carbon nitride toward elemental sulfur at 190 °C were 88.8% and 83%, respectively. Both samples... 

This work concerns simultaneous determination of relative permeability, capillary pressure, pore size distribution (PSD), and residual oil saturation data by optimization of well testing data, and introduces a new capillary pressure relationship, based on the Weibull distribution function, for direct determination of the PSD function from capillary pressure parameters. Three consecutive injection, fall off, and production well tests are performed on a predefined synthetic reservoir through simulation, and an optimization algorithm is used to find the parameters of relative permeability and capillary pressure curves as well as the value of residual oil saturation. The PSD function is also... 

This study investigates the effects of polymer concentration and solvent type on the pore size distribution (PSD) of the fabricated gas-liquid membrane contactors (MCs). Eighteen flat-sheet MCs are fabricated using polysulfone (PSf) and polyethersulfone (PES) polymers, with polymer concentration of 10%, 15%, and 20%. Dimethylformamide (DMF) and n-methyl-2-pyrrolidone (NMP) solvents are used to prepare the polymeric solutions. The role of polyvinylpyrrolidone (PVP) on the mean pore size of MCs is also studied. Scanning electron microscope (SEM) analysis is applied to visualize the pore system of the fabricated MCs. Image processing technique is used to obtain the PSD of the fabricated MCs... 

In the present study, a magnetic core-shell metal-organic framework (Fe3O4@PAA@UiO-66-NH2) nanocomposite was synthesized by a facile step-by-step self-assembly technique and used for selective adsorption of the anti-cancer Quercetin (QCT) drug. The synthesized nanocomposite was well characterized using FTIR, XRD, BET, FESEM, and TEM techniques. The adsorption kinetics and isotherms of the magnetic nanocomposites for QCT were investigated in detail at different initial concentrations and temperatures. It was found that the experimental adsorption kinetic and isotherm data were precisely explained by the pseudo-second-order kinetic and Langmuir isotherm models. Moreover, the selective... 

In the present study, a magnetic core-shell metal-organic framework (Fe3O4@PAA@UiO-66-NH2) nanocomposite was synthesized by a facile step-by-step self-assembly technique and used for selective adsorption of the anti-cancer Quercetin (QCT) drug. The synthesized nanocomposite was well characterized using FTIR, XRD, BET, FESEM, and TEM techniques. The adsorption kinetics and isotherms of the magnetic nanocomposites for QCT were investigated in detail at different initial concentrations and temperatures. It was found that the experimental adsorption kinetic and isotherm data were precisely explained by the pseudo-second-order kinetic and Langmuir isotherm models. Moreover, the selective... 

Herein, MIL-101(Fe), CoFe2O4, novel binary (MIL-101(Fe)/CoFe2O4, MIL-101(Fe)/GO and CoFe2O4/GO), and ternary (MIL-101(Fe)/CoFe2O4/(3%)GO and MIL-101(Fe)/CoFe2O4/(7%)GO) magnetic composites based upon the MIL-101(Fe) were synthesized. The XRD, FESEM, TEM, EDX, BET-BJH, FTIR, VSM, DRS, PL, EIS and other electrochemical analyses were applied to characterize samples. The MIL/CoFe2O4/(3%)GO demonstrated the best performance compared to other samples for visible light photocatalytic and photo-Fenton-like degradation of Direct Red 23 (DtR-23), Reactive Red 198 (ReR-198) dyes as well as Tetracycline Hydrochloride (TC-H) antibiotic. Degradation of dyes using the ternary composite after 70 min of... 

In this work, Ag nanoparticles were loaded on ZIF-67 covered by graphene oxide (Ag/ZIF-67@GO), and its catalytic performance was studied for the heterogeneous activation of peroxymonosulfate (PMS) under visible-light. The catalyst surface morphology and structure were analyzed by FT-IR, XRD, XPS, DRS, FE-SEM, EDX, TEM, BET, ICP-AES and TGA analysis. The efficacy of PMS activation by the Ag/ZIF-67@GO under visible light was assessed by phenol degradation and E. coli inactivation. Phenol was completely degraded within 30 min by HO•, SO4•− and O2•− generated through the photocatalytic PMS activation. In addition, total E. coli inactivation was attained in 15 min that confirmed the highly... 

Carbonaceous materials (CMs) have been applied extensively for enhancing the catalytic performance of environmental catalysts, however, the self-catalytic mechanism of CMs for groundwater remediation is rarely investigated. Herein, we unveiled the catalytic ability of various CMs via Fe(III) reduction through polyvinyl alcohol-coated calcium peroxide nanoparticles (PVA@nCP) for trichloroethylene (TCE) removal. Among selected CMs (graphite (G), biochar (BC) and activated carbon (AC)), BC and AC showed enhancement of TCE removal of 89% and 98% via both adsorption and catalytic degradation. BET and SEM analyses showed a higher adsorption capacity of AC (27.8%) than others. The generation of... 

Carbonaceous materials (CMs) have been applied extensively for enhancing the catalytic performance of environmental catalysts, however, the self-catalytic mechanism of CMs for groundwater remediation is rarely investigated. Herein, we unveiled the catalytic ability of various CMs via Fe(III) reduction through polyvinyl alcohol-coated calcium peroxide nanoparticles (PVA@nCP) for trichloroethylene (TCE) removal. Among selected CMs (graphite (G), biochar (BC) and activated carbon (AC)), BC and AC showed enhancement of TCE removal of 89% and 98% via both adsorption and catalytic degradation. BET and SEM analyses showed a higher adsorption capacity of AC (27.8%) than others. The generation of...