Catalysis and Reaction Engineering Commons^™

Electrochemically Active Biofilm Assisted Synthesis Of Ag@Ceo2 Nanocomposites For Antimicrobial Activity, Photocatalysis And Photoelectrodes, Mohammad Mansoob Khan Dr, S. A. Ansari, J. H. Lee, M. O. Ansari, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Ag@CeO2 nanocomposites were synthesized by a biogenic and green approach using electrochemically active biofilms (EABs) as a reducing tool. The as-synthesized Ag@CeO2 nanocomposites were characterized and used in antimicrobial, visible light photocatalytic and photoelectrode studies. The Ag@CeO2 nanocomposites showed effective and efficient bactericidal activities and survival test against Escherichia coli O157:H7, and Pseudomonas aeruginosa. The as-synthesized Ag@CeO2 nanocomposites also exhibited enhanced visible light photocatalytic degradation of 4-nitrophenol and methylene blue than pure CeO2. A photocatalytic investigation showed that the Ag@CeO2 nanocomposites possessed excellent visible light photocatalytic activities compared to pure CeO2. Electrochemical impedance spectroscopy and photocurrent measurements showed that the …

Au@Tio2 Nanocomposites For The Catalytic Degradation Of Methyl Orange And Methylene Blue: An Electron Relay Effect, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Au@TiO2 nanocomposites were used for the catalytic degradation of methyl orange and methylene blue by NaBH4. A detail pathway for step by step reduction, oxidation and complete mineralization of intermediates into the respective end-products was established by UV-vis spectroscopy, chemical oxygen demand, ion chromatography and cyclic voltammetry (CV). CV studies confirmed that the dyes were reduced and oxidized to the end-products by NaBH4 in the presence of Au@TiO2 nanocomposites and O2•, •OH and HO2• radicals generated in-situ. Results suggest that Au@TiO2 nanocomposites not only assist in the decolorization of dyes, but also promote their complete mineralization into harmless end-products.

Highly Visible Light Active Ag@Zno Nanocomposites Synthesized By Gel-Combustion Route, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Highly visible light active 1% and 3% Ag@ZnO nanocomposites were synthesized via a gel combustion route using citric acid as a fuel. The formation of the nanocomposites with enhanced properties was confirmed using a range of characterization techniques, photocatalysis and photoelectrochemical studies. Compared to the pristine ZnO nanoparticles, the Ag@ZnO nanocomposites exhibited enhanced visible light photocatalytic activity for the degradation of methylene blue and photoelectrochemical response. A mechanism was proposed to account for the photocatalytic activities of the Ag@ZnO nanocomposite that showed the surface plasmon resonance (SPR) of Ag is an effective way of enhancing the visible light photocatalytic activities.

Solar And Visible Light Driven Photocatalysis For Sacrificial Hydrogen Generation And Water Detoxification With Chemically Modified Ti02, Pankaj Chowdhury

PC

Photocatalysis is a recognized approach where light energy is employed to excite the semiconductor material producing electron/hole pair which eventually involves in the detoxification of pollutants and/or water splitting producing hydrogen. Existing photocatalysts suffer from poor activity or no activity in visible light irradiation which restricts them from solar light utilization. This work is focused on two key applications of photocatalysis (i) sacrificial hydrogen generation, and (ii) phenol degradation in visible and/or solar light. Platinum was loaded on TiO2 photocatalyst by solar photo-deposition method. Eosin Y dye was used as a sensitizer for sensitization of platinum loaded TiO2 photocatalyst. The …

Construction And Reactivity Screening Of A Surface Composition Gradient For Combinatorial Discovery Of Electro-Oxidation Catalysts, Shrisudersan Jayaraman, Andrew C. Hillier

Andrew C. Hillier

Materials possessing gradients in composition or structure are of interest for a range of applications, including the construction of functionally graded structural materials, as novel sensor and actuator platforms, and to control the site-specific binding of proteins and cells on surfaces. Gradients can also be used as sample libraries for combinatorial materials discovery that present an extremely dense sample set.

Head Unit Pioneer Avh - P4200dvd, Tri Nenty Uny

Tri nenty UNY

Pioneer AVH - P4200DVD

Bluetooth :

Menyambung telephone ke unit ini cukup menyakitkan. Aktifkan modus penemuan telephone serta unit selekasnya mendengarkan. Sesudah telephone sudah dibentuk pertama kalinya, itu benar-benar gampang. Hanya satu hal yang dibutuhkan, yaitu Bluetooth mesti diaktifkan, di telephone. Head unit automatis mendengarkan saat dekat. Menghubungkan amat cepat, umumnya kurun waktu satu atau dua detik. Pabrik Bluetooth bakal mengonsumsi saat seputar 30 detik. Modul ini dilengkapi dengan mikrofon bahwasanya saya sudah dipasang oleh kaca spion saya.

Band Gap Engineering Of Ceo2 Nanostructure Using An Electrochemically Active Biofilm For Visible Light Applications, S A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Narrowing the optical band gap of cerium oxide (CeO2) nanostructures is essential for visible light applications. This paper reports a green approach to enhance the visible light photocatalytic activity of pure CeO2 nanostructures (p-CeO2) through defect-induced band gap narrowing using an electrochemically active biofilm (EAB). X-ray diffraction, UV-visible diffuse reflectance/absorption spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, Raman spectroscopy, photoluminescence spectroscopy and high resolution transmission electron microscopy confirmed the defect-induced band gap narrowing of the CeO2 nanostructure (m-CeO2). The structural, optical, photocatalytic and photoelectrochemical properties also revealed the presence of structural defects caused by the reduction of Ce4+ to …

Modeling Stress Distributions In Anodic Alumina Films Prior To The Onset Of Pore Formation, Kurt R. Hebert, Ömer Ö. Çapraz, Shinsuke Ide, Pranav Shrotriya

Ömer Özgür Çapraz

Porous anodic oxide (PAO) films are produced when reactive metals such as Al and Ti are electrochemically oxidized in baths that dissolve the oxide. Research in PAObased devices has been stimulated by the self-organized hexagonally ordered pore arrays found for some anodizing conditions. The initiation and ordering of pores follows a morphological instability of the initially planar barrier oxide, upon reaching a critical oxide thickness.

Morphological Instability Leading To The Formation Of Self-Ordered Porous Anodic Oxide Films, Ömer Özgür Çapraz, Kurt R. Hebert, Pranav Shrotriya, Fanliang Gao, Wei Hong

Ömer Özgür Çapraz

Porous anodic oxide (PAO) films are grown by electrochemical polarization of Al, Ti, Zr, Nb, Hf, and W in baths that dissolve the oxide. Procedures to grow films with highly ordered arrangements of nanoscale pores have led to the extensive use of PAO films as templates for nanostructured devices. The porous film geometry may be controlled precisely via the film formation voltage and bath composition (1). Recently, tracer studies and modeling showed that transport in the amorphous oxide involves both electrical migration and plastic flow (2,3). The oxide seems to behave as an incompressible material during steady-state growth of the …

Stress Distributions In Anodic Alumina Films Prior To The Onset Of Pore Formation, Ömer Ö. Çapraz, Pranav Shrotriya, Kurt R. Hebert

Ömer Özgür Çapraz

Porous anodic oxide (PAO) films are grown by electrochemical oxidation of valve metals in baths that dissolve the oxide. The self-organized hexagonal patterns of pores in these films have led to many investigations of PAO-based devices. However, the mechanisms of pore formation and ordering have not yet been fully explained. Recent experimental and modeling results indicate the importance of plastic flow during growth of self-ordered PAO.1 Here we investigated the origin of stress driving plastic flow, and the possible role of stress in the morphological instability leading to pore formation. We report the first measurements of the evolution of stress …

Tensile Stress Induced By Aluminum Corrosion, Ömer Ö. Çapraz, Kurt R. Hebert, Pranav Shrotriya, Gery R. Stafford

Ömer Özgür Çapraz

Stress corrosion cracking (SCC) is a critical problem affecting the safety and viability of both existing energy conversion systems and ones under consideration for future development. In SCC, chemical interactions of a metal with the environment during corrosion accelerate degradation of materials under tensile applied stress, by reducing the critical stress intensity for crack propagation. Many competing mechanisms for the effect of corrosion in SCC have been put forth, including formation of brittle oxide or hydride phases, stress concentration at corrosion pits, and absorption of hydrogen. An additional mechanism is based on observed generation of tensile stress during corrosion of …

Curvature Interferometry Based In-Situ Measurement Of Stresses Associated With Electrochemical Reactions, Ömer Ö. Çapraz, Pranav Shrotriya, Kurt R. Hebert

Ömer Özgür Çapraz

Anodization1 as well as dissolution2 of reactive metals such as aluminum results in buildup of significant levels of stresses on the reacting surface. In-situ measurement of stress evolution can provide remarkable insights into the associated electrochemical reactions and help in understanding the governing mechanisms. We report a curvature interferometry based technique for in-situ monitoring of stress evolution. Curvature interferometer is incorporated into the electrochemical cell and is used to monitor the curvature changes of the samples in order to determine the stress-thickness product of the film formed on the reacting surface.

Hydrodynamics Of A Novel Design Circulating Fluidized Bed Steam Reformer Operating In The Dense Suspension Upflow Regime, Moataz Bellah M. Mousa, Seif-Eddeen K. Fateen, Essam A. Ibrahim

Seif-Eddeen K Fateen

Circulating fluidized bed steam reformers (CFBSR) represent an important alternative for hydrogen production, a promising energy carrier. Although the reactor hydrodynamics play crucial role, modeling efforts to date are limited to one-dimensional models thus ignoring many of the flow characteristics of fluidized-beds that have strong effects on the reactor efficiency. The flow inside the riser is inherently complex and requires at least two-dimensional modeling to capture its details. In the present work, the Computational Fluid Dynamics (CFD) simulations of the hydrodynamics of the riser part of a novel CFBSR were carried out using two-phase Eulerian-Eulerian approach coupled with kinetic theory …

Highly Photoactive Sno2 Nanostructures Engineered By Electrochemically Active Biofilm, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This paper reports the defect-induced band gap narrowing of pure SnO2 nanostructures (p-SnO2) using an electrochemically active biofilm (EAB). The proposed approach is biogenic, simple and green. Systematic characterization of the modified SnO2 nanostructures (m-SnO2) revealed EAB-mediated defects in pure SnO2 nanostructures (p-SnO2). m-SnO2 nanostructures in visible light showed the enhanced photocatalytic degradation of p-nitrophenol and methylene blue compared to p-SnO2 nanostructures. Photoelectrochemical studies, such as electrochemical impedance spectroscopy and linear scan voltammetry, also revealed a significant increase in the visible light response of m-SnO2 compared to p-SnO2 nanostructures. The enhanced activities of m-SnO2 in visible light was attributed to …

Development Of A New Kinetic Model For Methanol To Propylene Process On Mn/H-Zsm-5 Catalyst, Naser Hady, Ali Niaei, Reza Nabavi, Ali Farzi, Masoud Navaei Shirazi

Seyed Reza nabavi

The activity of the H-ZSM-5 was modified by the addition of Ca, Mn, Cr, Fe, Ni, Ag, Ce and P. The highest selectivity of propylene was obtained over the Mn/H-ZSM-5 catalyst. The Mn modified catalyst was selected as the optimal catalyst and the kinetic study was carried out on it. All of the experiments were carried out in an isothermal fixed bed and plug flow reactor with the mixture of methanol and water. The temperature range was 400–550 °C and the weight hourly space velocities (WHSV) of methanol were: 2.51, 5.42, and 8.17 h–1. A reaction mechanism based on the …

Catalytic Or Thermal Reversed Flow Combustion Of Coal Mine Ventilation Air Methane: What Is Better Choice And When?, Krzysztof J. Gosiewski

Krzysztof Gosiewski

The paper presents a comparison of the two options of reverse flow reactors destined for the utilization of coal mine ventilation air methane by catalytic (CFRR) or thermal (TFRR) combustion. It has been shown that both solutions have advantages and drawbacks. The use of the catalyst significantly decreases reactor temperature and makes the operation becomes to be autothermal for methane concentrations lower than in TFRR (even as low as over 0.06 vol.%). On the other hand when methane is combusted, particularly if average concentration is higher than ca. 0.4 vol.% the maximum temperature in the reactor appears to be too …

Termodynamika Procesowa I Techniczna Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Tematyka Prac Dyplomowych Dla Studentów Wydziału Mechaniczno-Energetycznego Pwr., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Tematyka Prac Dyplomowych Dla Studentów Wydziału Chemicznego Pwr., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Mechanika Płynów Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Functional Carbons And Carbon Nanohybrids For The Catalytic Conversion Of Biomass To Renewable Chemicals In The Condensed Phase, John Matthiesen, Thomas Hoff, Chi Liu, Charles Pueschel, Radhika Rao, Jean-Philippe Tessonnier

Jean-Philippe Tessonnier

The production of chemicals from lignocellulosic biomass provides opportunities to synthesize chemicals with new functionalities and grow a more sustainable chemical industry. However, new challenges emerge as research transitions from petrochemistry to biorenewable chemistry. Compared to petrochemisty, the selective conversion of biomass-derived carbohydrates requires most catalytic reactions to take place at low temperatures (< 300 °C) and in the condensed phase to prevent reactants and products from degrading. The stability of heterogeneous catalysts in liquid water above the normal boiling point represents one of the major challenges to overcome. Herein, we review some of the latest advances in the field with an emphasis on the role of carbon materials and carbon nanohybrids in addressing this challenge.

A Kinetic Model For Ethylene Oligomerization Using Zirconium/Aluminum- And Nickel/Zinc-Based Catalyst Systems In A Batch Reactor, Adil A. Mohammed, Seif-Eddeen K. Fateen, Tamer S. Ahmed, Tarek M. Moustafa

Seif-Eddeen K Fateen

The aim of this work is to develop a kinetic model of the oligomerization of ethylene to Linear Alpha Olefins (LAOs) for zirconium/aluminum and nickel/zinc catalyst systems. The development of such model helps in the study of the behavior of industrial LAOs reactors as well as in the optimization of their operation. The kinetic model was developed based on a four-step mechanism: site activation, initiation and propagation, chain transfer and site deactivation. A novel stochastic optimization algorithm, Intelligent Firefly Algorithm, was used to obtain the kinetic model parameters that best fit the available experimental data that were obtained from published …

Band Gap Engineered Tio2 Nanoparticles For Visible Light Induced Photoelectrochemical And Photocatalytic Studies, Mohammad Mansoob Khan Dr, S A. Ansari, D Pradhan, D H. Han, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Visible light-active TiO2 (m-TiO2) nanoparticles were obtained by an electron beam treatment of commercial TiO2 (p-TiO2) nanoparticles. The m-TiO2 nanoparticles exhibited a distinct red-shift in the UV-visible absorption spectrum and a much narrower band gap (2.85 eV) due to defects as confirmed by diffuse reflectance spectroscopy (DRS), photoluminescence (PL), X-ray diffraction, Raman spectroscopy, electron paramagnetic resonance, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and linear scan voltammetry (LSV). The XPS revealed changes in the surface states, composition, Ti4+ to Ti3+ ratio, and oxygen deficiencies in the m-TiO2. The valence band XPS, DRS and PL results were …

Selective Phenol Methylation To 2,6-Dimethylphenol In A Fluidized Bed Of Iron-Chromium Mixed Oxide Catalyst With O–Cresol Circulation, Witold Zukowski, Gabriela Berkowicz, Jerzy Baron, Stanisław Kandefer, Dariusz Jamanek, Stefan Szarlik, Zbigniew Wielgosz, Maria Zielecka

Witold Zukowski

Background 2,6-dimethylphenol (2,6-DMP) is a product of phenol methylation, especially important for the plastics industry. The process of phenol methylation in the gas phase is strongly exothermic. In order to ensure good temperature equalization in the catalyst bed, the process was carried out using a catalyst in the form of a fluidized bed - in particular, the commercial iron-chromium catalyst TZC-3/1. Results Synthesis of 2,6-dimethylphenol from phenol and methanol in fluidized bed of iron-chromium catalyst was carried out and the fluidization of the catalyst was examined. Stable state of fluidized bed of iron-chromium catalyst was achieved. The measured velocities allowed …

Conversion Of Nitrogen Compounds Into Nitrogen Oxides During Combustion In A Fluidised Bed Reactor, Witold Zukowski, Beata Kowarska

Witold Zukowski

Combustion processes of alternative fuels with high nitrogen content can cause nitrogen oxides emission which is unacceptable from an environmental and legal point of view. Reactions of nitrogen compounds, e.g. ammonia or heterocyclic compounds, are complex and there is a lack of specialized complete knowledge about them. This paper reports processes of propane combustion in a fluidized bed reactor without and with ammonia or pyridine addition into the reaction zone, especially nitrogen compound conversion into NxOy. Ammonia is converted into NxOy up to 78%, and pyridine up to 93%. The main product of their reactions is NO (average 97%). Residual …

Optimization Of Gold Nanoparticles Synthesis By Stainless Steel For H2o2 And Glucose Detection, T. H. Han, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

The synthesis of (+)AuNPs procedure using a stainless-steel mesh was optimized. The optimal synthetic parameters were found to be one piece of stainless-steel mesh (22.5 cm2 in surface area) in 100 mL of a 1 mM precursor, precursor solution pH 4, and reaction temperature of 30°C. Under the optimal conditions, the as-synthesized (+)AuNPs were highly positively charged (+24.2 mV). Therefore, the as-synthesized (+)AuNPs act as a peroxidase mimic and provide a simple, fast, highly sensitive and selective colorimetric method for H2O2 detection with a detection limit of 0.06 mM in the linear range from 0.06 mM to 4.29 mM.

A Universal Procedure For Crude Glycerol Purification From Different Feedstocks In Biodiesel Production: Experimental And Simulation Study, Yang Xiao, Guomin Xiao, Arvind Varma

Yang Xiao

Novel Ag@Tio2 Nanocomposite Synthesized By Electrochemically Active Biofilm For Nonenzymatic Hydrogen Peroxide Sensor, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

A novel nonenzymatic sensor for H2O2 was developed based on an Ag@TiO2 nanocomposite synthesized using a simple and cost effective approach with an electrochemically active biofilm. The optical, structural, morphological and electrochemical properties of the as-prepared Ag@TiO2 nanocomposite were examined by UV-vis spectroscopy, x-ray diffraction, transmission electron microscopy and cyclic voltammetry (CV). The Ag@TiO2 nanocomposite was fabricated on a glassy carbon electrode (GCE) and their electrochemical performance was analyzed by CV, differential pulse voltammetry and electrochemical impedance spectroscopy. The Ag@TiO2 nanocomposite modified GCE (Ag@TiO2/GCE) displayed excellent performance towards H2O2 sensing at −0.73 V in the linear response range from 0.83 …

A Novel Mixed Metallic Oxygen Carrier For Chemical Looping Combustion: Preparation, Characterization And Kinetic Modeling, Mohammad Rezwanul Quddus

Mohammad Rezwanul Quddus

In last decades, significant concerns have been raised regarding the global warming effect. To date, about one-third of the total anthropogenic CO2 emission results from power generation using fossil based fuel and CO2 is the main contributor to global warming. Therefore, technologies for efficient capture of CO2 are becoming of great value. In this respect, Chemical-Looping Combustion (CLC) has received significant attention as a promising technology facilitating concurrent CO2 capture and power generation. This non-conventional technique employs a solid carrier, known as oxygen carrier, to supply oxygen and facilitates combustion process in absence of N2 diluted air. Therefore, the combustion …

Simultaneous Enhancement Of The Methylene Blue Degradation And Power Generation In Microbial Fuel Cell By Gold Nanoparticles, Mohammad Mansoob Khan Dr, T. H. Han, S. Kalathil, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This study examined the effect of positively charged gold nanoparticles ((+)AuNPs) on the enhancement of methylene blue (MB) degradation in microbial fuel cell (MFC) cathode. The maximum electricity production of 36.56 mW/m2 and complete MB degradation were achieved simultaneously. The MFC performance and MB degradation are strictly dependent on cathodic conditions, such as N2 bubbling, air bubbling and addition of H2O2. MB was reduced rapidly under anaerobic condition, whereas complete oxidative mineralization of MB occurred in the presence of dissolved oxygen (DO) or H2O2. (+)AuNPs enhanced the electricity generation in the MFCs involving MB degradation owing to its electron relay …