The CO 2-oxydehydrogenation of ethane was investigated over a series of Cr impregnated ZSM-5-ZrO ... more The CO 2-oxydehydrogenation of ethane was investigated over a series of Cr impregnated ZSM-5-ZrO 2 nanocatalysts varying in zirconia content with the aim of improving catalytic performance of Cr/ZSM-5 catalyst in the ODH reaction and also exploring the appropriate ZrO 2 content. It was found that ZrO 2 addition to ZSM-5 strongly modifies catalytic performance of Cr/ZSM-5, although the changes in the catalytic behaviour depend on the ZrO 2 content. The highest activity was reached on Cr supported ZrO 2-doped ZSM-5 containing 10 wt.% zirconia.
Journal of Materials Science: Materials in Electronics, 2017
Zinc oxide (ZnO) and Titanium dioxide (TiO 2) nano-particles were synthesized by sol-gel method. ... more Zinc oxide (ZnO) and Titanium dioxide (TiO 2) nano-particles were synthesized by sol-gel method. Next, (ZnO/TiO 2) mono, double and multilayers were deposited by spin-coating technique on glass substrates. Structure, chemical bonds, optical properties, nano-particles size, surface morphology and multilayers structure were studied using X-ray diffraction (XRD) technique, Fourier Transform Infrared and UV-Vis-NIR spectroscopy, Transmission Electron Microscopy and Field Emission Scanning Electron Microscopy (FESEM), respectively. XRD results described the Wurtzite crystalline phase for ZnO and Anatase phase for TiO 2 layers. Moreover based on Scherer equation, the TiO 2 and ZnO nano-crystallites sizes were estimated about 11 and 25 nm respectively. XRD results also described increase of the layers crystallinity with increase of the layers number. Optical studies described despite of band-gap widening, transparency decreased with increase of layers number. This effect was attributed to the thin films thickness. TEM images described that the TiO 2 nano-particles were smaller than ZnO one while more coalesced. FESEM images revealed that the multilayers contained of a flat and homogenous surface.
Antibiotic pollution via wastewaters has led to many environmental problems. In this work, to rem... more Antibiotic pollution via wastewaters has led to many environmental problems. In this work, to remove ciprofloxacin which is an antibiotic from water, foil photocatalyst of zinc oxide nanowires doped with copper and cerium oxides was applied under UV light irradiation. An empirical model was developed to determine the photocatalyst activity using response surface methodology. The independent variables were the concentrations of precursors, copper and cerium nitrates in the coating solution. The F-value and p-value of the model showed the accuracy of the model. The statistical analysis indicated that copper oxide had larger effect on the response than cerium oxide. The optimized catalyst was determined and characterized using ICP, XRD, SEM and MIP techniques. The results of this work which are comparable to those of the previous studies have the advantage of easy separation of the photocatalyst from water without using a centrifuge.
In this work, the behavior of a single-type industrial methanol reactor while the 5% CO was injec... more In this work, the behavior of a single-type industrial methanol reactor while the 5% CO was injected into the 95% of feed was investigated. For the dynamic simulation purposed, a heterogeneous one-dimensional model has been developed in the presence of long term catalyst deactivation. The performance of the reactor with CO injection to the feed entrance was investigated and the product and reactant mole fraction profiles of the aforesaid reactor were compared with that of a conventional single type (CMR) and membrane methanol reactor (MMR). The simulation results represent 14.24% and 22.93% enhancement in the yield of methanol production in comparison with MMR and CMR, respectively, while 5% CO was injected into the 95% of the feed. Also, by CO injection to the feed, water production during methanol synthesis via CO2 hydrogenation which accelerates the catalyst deactivation and reduces methanol production rate, is reduced greatly. Additionally, nowadays CO is an important cause of p...
ABSTRACT A series of catalysts synthesized via the sol–gel method to study the effect of ZrO2 and... more ABSTRACT A series of catalysts synthesized via the sol–gel method to study the effect of ZrO2 and MgO and their mixture in ethane dehydrogenation over the Ni/ZrO2–MgO nanocatalyst in the presence of CO2/O2. The catalysts were characterized by XRD, FESEM, EDX, FTIR, and BET techniques. The homogenous dispersion of applied elements in the structure and on the surface of all synthesized catalysts was clear according to the XRD and EDX results, respectively. Synthesized ZrO2 formed small crystallites while MgO as a high crystalline material depicted large crystallites on the surface. Having these two in the ZrO2–MgO mixture controlled the observed large crystallite size of MgO and the particle size of the catalyst. The mixture of MgO and ZrO2 having both beneficial basic and acidic properties resulted in the better catalyst compared to ZrO2 and MgO. Finally, evaluating the effect of having NiO in the mixture of ZrO2–MgO confirmed the significant impact of Ni-based catalysts in oxidative dehydrogenation of ethane. Of course, these phases affected all together on the observed results. This cooperation mentioned as the synergistic effect in this study. The best catalyst among the studied ones was Ni/ZrO2–MgO that demonstrated an ethylene yield of 55.2%.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2010
Boron Neutron Capture Therapy (BNCT) is being studied as a possible radiotherapic treatment for s... more Boron Neutron Capture Therapy (BNCT) is being studied as a possible radiotherapic treatment for some cancer types. Neutron energy for penetrating into tissue should be in the epithermal range. Different methods are used for neutron production. Electron accelerators are an alternative way for producing neutrons in electron-photon-neutron processes. Optimization of electron/photon and photoneutron targets calculations with respect to electron energy, dimension (radius and thickness) and neutron yield were done by MCNPX Monte Carlo code. According to the results, a hybrid photoneutron source including BeD 2 and Tungsten has been introduced.
Combinatorial Chemistry & High Throughput Screening
Aim and Objective: Production of light olefins from methanol was studied over SAPO-34 molecular s... more Aim and Objective: Production of light olefins from methanol was studied over SAPO-34 molecular sieves exploring the effect of mono and dual templates. Herein, the single templates of TEA, morpholine and mixed template of TEA/morpholine (equal molar ratio of TEA and morpholine) were used to synthesize SAPO-34 catalysts. Materials and Methods: The prepared samples were prepared via hydrothermal synthesis method and characterized with XRD, FESEM, PSD, EDX, BET and FTIR techniques. Results: It was found that the crystallinity decreased upon applying TEA as template and also it can be noted that the intensity of the SAPO-34 phase peaks increased by increasing the morpholine in template mixture. Production of much smoother particles for the catalyst synthesized with binary template mixture of TEA/morpholine can be depended on the crystallinity increase. Si incorporation value was decreased for the catalyst with a major phase of SAPO-5 (topological structure of AFI). It is indicative that...
In a continuing effort to realize the simultaneous hydrogen and methanol production via the auto-... more In a continuing effort to realize the simultaneous hydrogen and methanol production via the auto-thermal methanol synthesis process, the effect of two different hydrogen redistribution strategies along a double-membrane reactor has been considered. A steady-state one-dimensional heterogeneous model was developed to compare two strategies applied in the operation of the auto-thermal methanol synthesis. It was found that the counter-current configuration exhibited the better performance compared to the reactor operated in the co-current mode from both the economic and environmental points of view. This superiority is ascribed to the establishment of a more favourable temperature profile along the reactor and also more hydrogen extraction from the reaction zone. Moreover, the influence of some operating variables was investigated on the performance of the auto-thermal double-membrane reactor in the counter-current configuration. The results suggest that utilizing this configuration for...
The catalytic performance of nanostructured Ni-Co/Al2O3-ZrO2 catalysts, prepared by ultrasound-as... more The catalytic performance of nanostructured Ni-Co/Al2O3-ZrO2 catalysts, prepared by ultrasound-assisted impregnation method was examined in the dry reforming of methane. The effect of irradiation power and irradiation time have been studied by changing time (0, 20, 80min) and power of the sonication (30, 60, 90W) during the synthesis which resulted in different physiochemical properties of the nanocatalyst. The nanocatalysts were characterized by XRD, FESEM, PSD, EDX, TEM, TPR-H2, BET, FTIR and TG analyses. Based on the characterization results, ultrasound treatment endowed the sample with more uniform and smaller nanoparticles; higher surface area, stronger metal-support interaction and more homogenous dispersion. Moreover, the analyses exhibited smaller particles with higher surface area and less population of particle aggregates at longer and highly irradiated nanocatalysts. The nanocatalyst irradiated at 90W for 80min (the longest irradiation time and the most intense power) sho...
ABSTRACT The Ni–Co/Al2O3–MgO nanocatalysts with different Al/Mg ratios were synthesized via sonoc... more ABSTRACT The Ni–Co/Al2O3–MgO nanocatalysts with different Al/Mg ratios were synthesized via sonochemistry method and applied in CH4/CO2 reforming. In order to investigate the effect of ultrasonic irradiation, Ni–Co/Al2O3–MgO nanocatalyst with Al2O3/MgO = 1.5 was also prepared via impregnation method. All samples were characterized by XRD, FESEM, PSD, BET and FTIR techniques. However, it should be noted that the sonochemistry method results in a better dispersion, smaller particle size, higher specific area and uniform morphology as well as better catalytic performance in comparison with the impregnation. Although among the prepared samples via sonochemistry, the Ni–Co/Al2O3–MgO nanocatalyst with Al2O3/MgO = 5 showed higher dispersion, better morphology, smaller crystal size, superior active phase distribution and higher specific surface area. Due to the better textural properties, the Ni–Co/Al2O3–MgO nanocatalyst with Al2O3/MgO = 5 shows a good catalytic performance, consequently.
The CO 2-oxydehydrogenation of ethane was investigated over a series of Cr impregnated ZSM-5-ZrO ... more The CO 2-oxydehydrogenation of ethane was investigated over a series of Cr impregnated ZSM-5-ZrO 2 nanocatalysts varying in zirconia content with the aim of improving catalytic performance of Cr/ZSM-5 catalyst in the ODH reaction and also exploring the appropriate ZrO 2 content. It was found that ZrO 2 addition to ZSM-5 strongly modifies catalytic performance of Cr/ZSM-5, although the changes in the catalytic behaviour depend on the ZrO 2 content. The highest activity was reached on Cr supported ZrO 2-doped ZSM-5 containing 10 wt.% zirconia.
Journal of Materials Science: Materials in Electronics, 2017
Zinc oxide (ZnO) and Titanium dioxide (TiO 2) nano-particles were synthesized by sol-gel method. ... more Zinc oxide (ZnO) and Titanium dioxide (TiO 2) nano-particles were synthesized by sol-gel method. Next, (ZnO/TiO 2) mono, double and multilayers were deposited by spin-coating technique on glass substrates. Structure, chemical bonds, optical properties, nano-particles size, surface morphology and multilayers structure were studied using X-ray diffraction (XRD) technique, Fourier Transform Infrared and UV-Vis-NIR spectroscopy, Transmission Electron Microscopy and Field Emission Scanning Electron Microscopy (FESEM), respectively. XRD results described the Wurtzite crystalline phase for ZnO and Anatase phase for TiO 2 layers. Moreover based on Scherer equation, the TiO 2 and ZnO nano-crystallites sizes were estimated about 11 and 25 nm respectively. XRD results also described increase of the layers crystallinity with increase of the layers number. Optical studies described despite of band-gap widening, transparency decreased with increase of layers number. This effect was attributed to the thin films thickness. TEM images described that the TiO 2 nano-particles were smaller than ZnO one while more coalesced. FESEM images revealed that the multilayers contained of a flat and homogenous surface.
Antibiotic pollution via wastewaters has led to many environmental problems. In this work, to rem... more Antibiotic pollution via wastewaters has led to many environmental problems. In this work, to remove ciprofloxacin which is an antibiotic from water, foil photocatalyst of zinc oxide nanowires doped with copper and cerium oxides was applied under UV light irradiation. An empirical model was developed to determine the photocatalyst activity using response surface methodology. The independent variables were the concentrations of precursors, copper and cerium nitrates in the coating solution. The F-value and p-value of the model showed the accuracy of the model. The statistical analysis indicated that copper oxide had larger effect on the response than cerium oxide. The optimized catalyst was determined and characterized using ICP, XRD, SEM and MIP techniques. The results of this work which are comparable to those of the previous studies have the advantage of easy separation of the photocatalyst from water without using a centrifuge.
In this work, the behavior of a single-type industrial methanol reactor while the 5% CO was injec... more In this work, the behavior of a single-type industrial methanol reactor while the 5% CO was injected into the 95% of feed was investigated. For the dynamic simulation purposed, a heterogeneous one-dimensional model has been developed in the presence of long term catalyst deactivation. The performance of the reactor with CO injection to the feed entrance was investigated and the product and reactant mole fraction profiles of the aforesaid reactor were compared with that of a conventional single type (CMR) and membrane methanol reactor (MMR). The simulation results represent 14.24% and 22.93% enhancement in the yield of methanol production in comparison with MMR and CMR, respectively, while 5% CO was injected into the 95% of the feed. Also, by CO injection to the feed, water production during methanol synthesis via CO2 hydrogenation which accelerates the catalyst deactivation and reduces methanol production rate, is reduced greatly. Additionally, nowadays CO is an important cause of p...
ABSTRACT A series of catalysts synthesized via the sol–gel method to study the effect of ZrO2 and... more ABSTRACT A series of catalysts synthesized via the sol–gel method to study the effect of ZrO2 and MgO and their mixture in ethane dehydrogenation over the Ni/ZrO2–MgO nanocatalyst in the presence of CO2/O2. The catalysts were characterized by XRD, FESEM, EDX, FTIR, and BET techniques. The homogenous dispersion of applied elements in the structure and on the surface of all synthesized catalysts was clear according to the XRD and EDX results, respectively. Synthesized ZrO2 formed small crystallites while MgO as a high crystalline material depicted large crystallites on the surface. Having these two in the ZrO2–MgO mixture controlled the observed large crystallite size of MgO and the particle size of the catalyst. The mixture of MgO and ZrO2 having both beneficial basic and acidic properties resulted in the better catalyst compared to ZrO2 and MgO. Finally, evaluating the effect of having NiO in the mixture of ZrO2–MgO confirmed the significant impact of Ni-based catalysts in oxidative dehydrogenation of ethane. Of course, these phases affected all together on the observed results. This cooperation mentioned as the synergistic effect in this study. The best catalyst among the studied ones was Ni/ZrO2–MgO that demonstrated an ethylene yield of 55.2%.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2010
Boron Neutron Capture Therapy (BNCT) is being studied as a possible radiotherapic treatment for s... more Boron Neutron Capture Therapy (BNCT) is being studied as a possible radiotherapic treatment for some cancer types. Neutron energy for penetrating into tissue should be in the epithermal range. Different methods are used for neutron production. Electron accelerators are an alternative way for producing neutrons in electron-photon-neutron processes. Optimization of electron/photon and photoneutron targets calculations with respect to electron energy, dimension (radius and thickness) and neutron yield were done by MCNPX Monte Carlo code. According to the results, a hybrid photoneutron source including BeD 2 and Tungsten has been introduced.
Combinatorial Chemistry & High Throughput Screening
Aim and Objective: Production of light olefins from methanol was studied over SAPO-34 molecular s... more Aim and Objective: Production of light olefins from methanol was studied over SAPO-34 molecular sieves exploring the effect of mono and dual templates. Herein, the single templates of TEA, morpholine and mixed template of TEA/morpholine (equal molar ratio of TEA and morpholine) were used to synthesize SAPO-34 catalysts. Materials and Methods: The prepared samples were prepared via hydrothermal synthesis method and characterized with XRD, FESEM, PSD, EDX, BET and FTIR techniques. Results: It was found that the crystallinity decreased upon applying TEA as template and also it can be noted that the intensity of the SAPO-34 phase peaks increased by increasing the morpholine in template mixture. Production of much smoother particles for the catalyst synthesized with binary template mixture of TEA/morpholine can be depended on the crystallinity increase. Si incorporation value was decreased for the catalyst with a major phase of SAPO-5 (topological structure of AFI). It is indicative that...
In a continuing effort to realize the simultaneous hydrogen and methanol production via the auto-... more In a continuing effort to realize the simultaneous hydrogen and methanol production via the auto-thermal methanol synthesis process, the effect of two different hydrogen redistribution strategies along a double-membrane reactor has been considered. A steady-state one-dimensional heterogeneous model was developed to compare two strategies applied in the operation of the auto-thermal methanol synthesis. It was found that the counter-current configuration exhibited the better performance compared to the reactor operated in the co-current mode from both the economic and environmental points of view. This superiority is ascribed to the establishment of a more favourable temperature profile along the reactor and also more hydrogen extraction from the reaction zone. Moreover, the influence of some operating variables was investigated on the performance of the auto-thermal double-membrane reactor in the counter-current configuration. The results suggest that utilizing this configuration for...
The catalytic performance of nanostructured Ni-Co/Al2O3-ZrO2 catalysts, prepared by ultrasound-as... more The catalytic performance of nanostructured Ni-Co/Al2O3-ZrO2 catalysts, prepared by ultrasound-assisted impregnation method was examined in the dry reforming of methane. The effect of irradiation power and irradiation time have been studied by changing time (0, 20, 80min) and power of the sonication (30, 60, 90W) during the synthesis which resulted in different physiochemical properties of the nanocatalyst. The nanocatalysts were characterized by XRD, FESEM, PSD, EDX, TEM, TPR-H2, BET, FTIR and TG analyses. Based on the characterization results, ultrasound treatment endowed the sample with more uniform and smaller nanoparticles; higher surface area, stronger metal-support interaction and more homogenous dispersion. Moreover, the analyses exhibited smaller particles with higher surface area and less population of particle aggregates at longer and highly irradiated nanocatalysts. The nanocatalyst irradiated at 90W for 80min (the longest irradiation time and the most intense power) sho...
ABSTRACT The Ni–Co/Al2O3–MgO nanocatalysts with different Al/Mg ratios were synthesized via sonoc... more ABSTRACT The Ni–Co/Al2O3–MgO nanocatalysts with different Al/Mg ratios were synthesized via sonochemistry method and applied in CH4/CO2 reforming. In order to investigate the effect of ultrasonic irradiation, Ni–Co/Al2O3–MgO nanocatalyst with Al2O3/MgO = 1.5 was also prepared via impregnation method. All samples were characterized by XRD, FESEM, PSD, BET and FTIR techniques. However, it should be noted that the sonochemistry method results in a better dispersion, smaller particle size, higher specific area and uniform morphology as well as better catalytic performance in comparison with the impregnation. Although among the prepared samples via sonochemistry, the Ni–Co/Al2O3–MgO nanocatalyst with Al2O3/MgO = 5 showed higher dispersion, better morphology, smaller crystal size, superior active phase distribution and higher specific surface area. Due to the better textural properties, the Ni–Co/Al2O3–MgO nanocatalyst with Al2O3/MgO = 5 shows a good catalytic performance, consequently.
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Papers by Farhad Rahmani