Intensification Of Gas Absorption In A Downward Flow Microbubble Bioreactor,
2019
CUNY City College
Intensification Of Gas Absorption In A Downward Flow Microbubble Bioreactor, Manizheh Ansari
Dissertations and Theses
Bioreactors are of interest for value-upgrading of stranded or waste industrial gases, such as CO, CH4, or syngas. Process economics requires reduction of reactor cost and size while maintaining high production rate via rapid delivery of gas feedstock to the liquid phase which in turn requires a high volumetric mass transfer rate (). One strategy to achieve this goal is to increase interfacial area density, a, to >3000 m2 m-3, while minimizing use of energy. Here we show a novel reactor column design that uses a micro-jet array to break feedstock at ambient pressure …
Mechanism Study Of Shale Gas Conversion Via Chemical Looping And Heterocatalytic Processes,
2019
West Virginia University
Mechanism Study Of Shale Gas Conversion Via Chemical Looping And Heterocatalytic Processes, Lei Bai
Graduate Theses, Dissertations, and Problem Reports (ETD)
The shale gas revolution has significantly changed the energy landscape in US. The technical-feasible, energy-effective schemes for shale gas combustion and utilization, especially from remote resources, have attracted increasing interest due to expensive transportation/distribution cost. In this research, for the first time, chemical looping combustion (CLC) of methane with inherent CO2 capture, oxidative coupling of methane (OCM) and dehydro-aromatization (DHA) of ethane are systematically studied as promising alternatives at O2-rich, O2-lean and non-oxidative conditions, respectively.
Chemical looping combustion is bridging clean fuel combustion in energy production with inherent CO2 capture. CLC utilized an oxygen …
Functionalization Of Iron Oxide Nanoparticles And The Impact On Surface Reactive Oxygen Species Generation For Potential Biomedical And Environmental Applications,
2019
University of Kentucky
Functionalization Of Iron Oxide Nanoparticles And The Impact On Surface Reactive Oxygen Species Generation For Potential Biomedical And Environmental Applications, Trang Mai
Theses and Dissertations--Chemical and Materials Engineering
Iron oxide nanoparticles (IONPs) have been widely studied for a variety of applications, from biomedical applications (e.g., cell separation, drug delivery, contrast agent for magnetic resonance imaging and magnetically mediated energy delivery for cancer treatment) to environmental remediations (e.g., heavy metal removal and organic pollutants degradation). It has been demonstrated that IONPs can induce the production of reactive oxygen species (ROS) via Fenton/Haber-Weiss reactions which has been shown to be one of the key underlying mechanisms of nanoparticles toxicity. This inherent toxicity of nanoparticles has been shown to enhance the efficacy of traditional cancer therapies such as chemotherapy and radiation. …
Impact Of Conformational Change, Solvation Environment, And Post-Translational Modification On Desulfurization Enzyme 2'-Hydroxybiphenyl-2-Sulfinate Desulfinase (Dszb) Stability And Activity,
2019
University of Kentucky
Impact Of Conformational Change, Solvation Environment, And Post-Translational Modification On Desulfurization Enzyme 2'-Hydroxybiphenyl-2-Sulfinate Desulfinase (Dszb) Stability And Activity, Landon C. Mills
Theses and Dissertations--Chemical and Materials Engineering
Naturally occurring enzymatic pathways enable highly specific, rapid thiophenic sulfur cleavage occurring at ambient temperature and pressure, which may be harnessed for the desulfurization of petroleum-based fuel. One pathway found in bacteria is a four-step catabolic pathway (the 4S pathway) converting dibenzothiophene (DBT), a common crude oil contaminant, into 2-hydroxybiphenyl (HBP) without disrupting the carbon-carbon bonds. 2’-Hydroxybiphenyl-2-sulfinate desulfinase (DszB), the rate-limiting enzyme in the enzyme cascade, is capable of selectively cleaving carbon-sulfur bonds. Accordingly, understanding the molecular mechanisms of DszB activity may enable development of the cascade as industrial biotechnology. Based on crystallographic evidence, we hypothesized that DszB …
Chemically Dealloyed Fe-Based Metallic Glass With Void Channels-Like Architecture For Highly Enhanced Peroxymonosulfate Activation In Catalysis,
2019
Edith Cowan University
Chemically Dealloyed Fe-Based Metallic Glass With Void Channels-Like Architecture For Highly Enhanced Peroxymonosulfate Activation In Catalysis, J.C. Wang, S.X. Liang, Z. Jia, W.C. Zhang, W.M. Wang, Y.J. Lui, J. Lu, L.C Zhang
Research outputs 2014 to 2021
Metallic glasses (MGs) with their intrinsic disordered atomic structure and widely controllable atomic components have recently emerged as fascinating functional materials in wastewater treatment. Compared to crystalline alloys, the less-noble atomic components in monolithic metallic glass are more efficient to be selectively dissolved during dealloying process. This work reported a facile chemical dealloying approach to fabricate a void channels-like structured MG with the elemental components of Fe73.5Si13.5B9Cu1Nb3 for methylene blue (MB) degradation. Results indicated that the dealloyed Fe73.5Si13.5B9Cu1Nb3 MGs with the void channels-like morphology presented a significant improvement of catalytic efficiency and reusability. The dye degradation reaction rate (kobs) of …
Reduction Of Nox Emissions In A Single Cylinder Diesel Engine Using Sncr With In-Cylinder Injection Of Aqueous Urea,
2019
University of North Florida
Reduction Of Nox Emissions In A Single Cylinder Diesel Engine Using Sncr With In-Cylinder Injection Of Aqueous Urea, Anthony Timpanaro
UNF Graduate Theses and Dissertations
The subject of this study is the effect of in-cylinder selective non-catalytic reduction (SNCR) of NOx emissions in diesel exhaust gas by means of direct injection of aqueous urea ((NH2)2CO) into the combustion chamber. A single cylinder diesel test engine was modified to accept an electronically controlled secondary common rail injection system to deliver the aqueous urea directly into the cylinder during engine operation.
Direct in-cylinder injection was chosen in order to ensure precise delivery of the reducing agent without the risk of any premature reactions taking place. Unlike direct in-cylinder injection of neat water, …
Engineering Of Earth-Abundant Electrochemical Catalysts,
2019
Virginia Commonwealth University
Engineering Of Earth-Abundant Electrochemical Catalysts, Dylan D. Rodene
Theses and Dissertations
Alternative energy research into hydrogen production via water electrolysis addresses environmental and sustainability concerns associated with fossil fuel use. Renewable-powered electrolyzers are foreseen to produce hydrogen if energy and cost requirements are achieved. Electrocatalysts reduce the energy requirements of operating electrolyzers by lowering the reaction kinetics at the electrodes. Platinum group metals (PGMs) tend to be utilized as electrocatalysts but are not readily available and are expensive. Ni1-xMox alloys, as low-cost and earth-abundant transition metal nanoparticles (NPs), are emerging as promising electrocatalyst candidates to replace expensive PGM catalysts in alkaline media. Pure-phase cubic and hexagonal Ni1-x …
Performance Of C2H4 Reductant In Activated-Carbon-Supported Mnox-Based Scr Catalyst At Low Temperatures,
2018
PetroChina, China
Performance Of C2H4 Reductant In Activated-Carbon-Supported Mnox-Based Scr Catalyst At Low Temperatures, Guangli Liu, Dongtai Han, Jie Cheng, Yongshi Feng, Wenbin Quan, Li Yang, Kozo Saito
Mechanical Engineering Faculty Publications
Hydrocarbons as reductants show promising results for replacing NH3 in SCR technology. Therefore, considerable interest exists for developing low-temperature (< 200 °C) and environmentally friendly HC-SCR catalysts. Hence, C2H4 was examined as a reductant using activated-carbon-supported MnOx-based catalyst in low-temperature SCR operation. Its sensitivity to Mn concentration and operating temperature was parametrically studied, the results of which showed that the catalyst activity followed the order of 130 °C > 150 °C > 180 °C with an optimized Mn concentration near 3.0 wt.%. However, rapid deactivation of catalytic activity also occurred when using C2H4 as the reductant. The mechanism of deactivation was explored and is …
Recent Progress In Pt-Based Catalysts For Oxygen Reduction Reaction,
2018
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China;
Recent Progress In Pt-Based Catalysts For Oxygen Reduction Reaction, Jing Li, Xin Feng, Zi-Dong Wei
Journal of Electrochemistry
One major challenge for a large-scale commercialization of the proton-exchange membrane fuel cells (PEMFCs) technologies that enable a shift to ‘zero-emission’ personal transportation, is the expensive and unstable Pt catalysts, which are mainly used to catalyze the sluggish kinetics of the oxygen reduction reaction (ORR) occurred on the air electrode of PEMFCs. Many research works have targets to improve the stability of Pt-based catalysts and to construct Pt/transitional metal alloys with low Pt loading amount. Herein, we provide a minireview for the Pt-based ORR catalysts based on our recent work, which covers a brief background introduction, the stability improvement of …
Stabilization Strategies Of Pt Catalysts Forproton Exchange Membrane Fuel Cells,
2018
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei, China;
Stabilization Strategies Of Pt Catalysts Forproton Exchange Membrane Fuel Cells, Da-Ping He, Shi-Chun Mu
Journal of Electrochemistry
The low service lifetime of proton exchange membrane fuel cells (PEMFCs) is the main bottleneck for their commercial applications. One of the main factors is that the expensive metal Pt catalyst is easy to degradation under the harsh working environment of PEMFC (such as variable voltage, strong acidity, gas-liquid two-phase flow), which leads to the inevitable decay of the catalytic performance, thus, seriously restricting the lifetime of PEMFC. Therefore, the electrochemical stability of Pt-based electrocatalysts has become an important and hot topic to improve the PEMFC lifetime. In this paper, we review the recent development in enhancing the stability of …
Fuel Cell Performance Curve After Mea Optimization Structural Optimization Of Low Pt Membrane Electrode Assembly,
2018
State Key Laboratory of Advanced Technology for Materials Synthesis and Progressing, Hubei Fuel Cell Key Laboratory, Wuhan University of Technology, Wuhan 430070, China;
Fuel Cell Performance Curve After Mea Optimization Structural Optimization Of Low Pt Membrane Electrode Assembly, Yan Rao, Shang Li, Fen Zhou, Tian Tian, Qing Zhong, Zhao-Hui Wan, Jin-Ting Tan, Mu Pan
Journal of Electrochemistry
Membrane electrode assemblies (MEAs) are the key component of proton exchange membrane fuel cell. For a long time, much attention has been paid to develop MEA technology. At present, the research, development and industrialization of fuel cell has entered a new era. More strict requirements for MEA, especially for the reduction of Pt loading with a challenging target of 0.125 mg·W-1 have to be met. In this paper, the performance losses under low Pt loading are analyzed in terms of activation polarization, ohm polarization and mass-transfer polarization. It is proposed that research should be focused on the activity of …
The Pilot Application Of Electrochemical Impedance Spectroscopy On Dynamic Proton Exchange Membrane Fuel Cell,
2018
Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China;
The Pilot Application Of Electrochemical Impedance Spectroscopy On Dynamic Proton Exchange Membrane Fuel Cell, Jian-Wei Guo, Jian-Long Wang
Journal of Electrochemistry
By analyzing Electrochemical Impedance Spectroscopy (EIS) in applications of dynamic proton exchange membrane fuel cell (PEMFC), bottlenecks which restrict EIS tool development have been pointed out in this paper. Though the high-frequency resistance in EIS is largely accepted as cell inner-resistance, this can only be applied for cell with low current. The low-frequency resistance is difficult to be realized due to its relation with mass transfer. Furthermore, the improved Randles equivalent circuits are built up preliminarily, thus, penetrating into studies for mass transfer reaction, cell operation/degeneration, and high temperature fuel cell. Inspiringly, EIS is becoming an analyzing tool for stack …
Fe-N Doped Hollow Carbon Nanospheres Linked By Carbon Nanotubes For Oxygen Reduction Reaction,
2018
Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China;University of Chinese Academy of Sciences, Beijing 100049, China;
Fe-N Doped Hollow Carbon Nanospheres Linked By Carbon Nanotubes For Oxygen Reduction Reaction, Ya-Lin Zhang, Chi Chen, Liang-Liang Zou, Zhi-Qing Zou, Hui Yang
Journal of Electrochemistry
The development of non-precious metal catalysts for oxygen reduction reaction (ORR) is essential for large-scale application of proton exchange membrane fuel cells. Herein, we present the in situ formed Fe-N doped hollow carbon nanospheres linked by carbon nanotubes composite, synthesized by using ZIF-8 as sacrificed template to form polydopamine (PDA) hollow nanospheres, followed by complexing with FeCl3, high temperature heat-treatment and NH3-etching. ZIF-8 was gradually decomposed simultaneously with PDA coating due to the loss of Zn2+ grabbed by PDA. NH3 etching resulted in the improved surface area, while the reducibility of NH3 resulted in …
Facile Synthesis Of Pt-Cu Alloy Nanodendrites As High-Performance Electrocatalysts For Oxygen Reduction Reaction,
2018
Institute of Fuel Cells, School of Mechanical Engineering, MOE Key Laboratory of Power & Machinery Engineering;
Facile Synthesis Of Pt-Cu Alloy Nanodendrites As High-Performance Electrocatalysts For Oxygen Reduction Reaction, Liu-Xuan Luo, Guang-Hua Wei, Shui-Yun Shen, Feng-Juan Zhu, Chang-Chun Ke, Xiao-Hui Yan, Jun-Liang Zhang
Journal of Electrochemistry
Structures and compositions have significant effects on the catalytic properties of nanomaterials. Herein, a facile etching-based method was employed to synthesize Pt-Cu nanodendrites (NDs) with uniform and homogeneous alloy structures for enhancing oxygen reduction reaction (ORR). The formation of dendritic morphology was ascribed to the etching effect caused by the oxidative etchants of the Br-/O2 pair. The atomic ratio of Pt/Cu in Pt-Cu NDs could be easily tuned by altering the ratio of the Pt/Cu precursors, without deteriorating the dendritic morphology. The most active carbon-supported Pt1Cu1 NDs (Pt1Cu1 NDs/C) exhibited the …
Caging Porous Co-N-C Nanocomposites In 3d Graphene As Active And Aggregation-Resistant Electrocatalyst For Oxygen Reduction Reaction,
2018
State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering,Carbon Research Laboratory, Dalian University ofTechnology, Dalian 116024, China
Caging Porous Co-N-C Nanocomposites In 3d Graphene As Active And Aggregation-Resistant Electrocatalyst For Oxygen Reduction Reaction, Lu-Yang Xiu, Meng-Zhou Yu, Peng-Ju Yang, Zhi-Yu Wang, Jie-Shan Qiu
Journal of Electrochemistry
Oxygen reduction reaction (ORR) is the cornerstone reaction of many renewable energy technologies such as fuel cells and rechargeable metal-air batteries. The Pt-based electrocatalysts exhibit the highest activity toward ORR, but their large implementation is greatly prohibiting by unaffordable cost and inferior durability. During electrode manufacturing and electrochemical reaction, severe aggregation of catalyst nanoparticles induced by size effect further limits the operational performance of electrocatalysts. We report a new strategy for fabrication of active and aggregation-resistant ORR electrocatalyst by caging metal-organic frameworks derived Co-N-C nanocomposites in permeable and porous 3D graphene cages via sprayed drying the mixed colloids of ZIF-67 …
Voltage Distribution Of Self-Humidifying Air-Cooled Pemfc,
2018
School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China; Clean Energy Research Center, Temasek Polytechnic, Singapore 529757, Singapore;
Voltage Distribution Of Self-Humidifying Air-Cooled Pemfc, Kai-Feng Tan, Wei-Rong Chen, Ming Han, Xue-Xia Zhang
Journal of Electrochemistry
In this work, the self-adaptive characteristics of self-humidifying air-cooled PEMFC stack was investigated. The performance and the unit-cell voltage distribution of the stack were measured and analyzed through the unit-cell I-V curve fitting. The operating conditions for this experimental study were set as follows: hydrogen pressure at the anode was 2 bar, the fan power used for the reactant oxygen feed and stack cooling was at 0.3 W, and the duration and time gap of water purged from hydrogen chamber were 1 s and 10 s, respectively. The experimental results showed that the self-humidifying air-cooled PEMFC stack used for this …
Research Progress In Hydrogen Evolution Low Noble/Non-Precious Metal Catalysts Of Water Electrolysis,
2018
State Key Laboratory of Electroanalytical Chemistry, Jilin Province Key Laboratory of Low Carbon Chemical Power Source, Changchun Institute of Applied Chemistry, Changchun 130022, China;Shcool of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China;
Research Progress In Hydrogen Evolution Low Noble/Non-Precious Metal Catalysts Of Water Electrolysis, Yang Li, Zhao-Yan Luo, Jun-Jie Ge, Chang-Peng Liu, Wei Xing
Journal of Electrochemistry
Hydrogen energy technology with hydrogen as an energy carrier is gaining more and more attention due to its cleanliness and high energy density. Hydrogen fuel cell vehicles have been listed as one of the ultimate energy technologies in the 21st century. Among them, sustainable hydrogen production technology is a necessary prerequisite for the future development of hydrogen energy economy. Electrolyzed water technology driven by renewable resources represents an important way to support the sustainable development of hydrogen energy economy. The development and utilization of high activity, low cost hydrogen evolution catalysts is a key factor in improving the efficiency and …
Progress Of Self-Humidifying Membrane Electrode Assembly For Low Temperature Proton Exchange Membrane Fuel Cell,
2018
The Key Laboratory of Fuel Cell Technology of Guangdong Province & The Key Laboratory of New Energy Technology of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, China;
Progress Of Self-Humidifying Membrane Electrode Assembly For Low Temperature Proton Exchange Membrane Fuel Cell, Bin Chi, Yue-Kun Ye, Shi-Jie Jiang, Shi-Jun Liao
Journal of Electrochemistry
The self/non-humidification membrane electrode assembly(SH-MEA)is an important pathway towards the self- humidification fuel cell and plays a crucial role for the large scale commercialization of low temperature proton exchange membrane fuel cell (LT-PEMFC), because it not only can reduce the volume and complexity of fuel cell system, resulting in the decrease of the cost, but also can improve the output power density of the fuel cell system. Currently, the researches on the self-humidifying MEA of LT-PEMFC mainly focus on three aspects: the preparation of self-humidification proton exchange membrane, the construction of self-humidification catalyst layer, and the construction of composite self-humidifying …
Palladium Adatoms On Gold Nanoparticles As Electrocatalysts For Ethanol Electro-Oxidation In Alkaline Solutions,
2018
Department of Pharmaceutical Engineering, Zhejiang Pharmaceutical College, Ningbo 315100, Zhejiang, P.R. China;Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, P.R. China;Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering,Xiamen University, Xiamen 361005, Fujian, P.R. China.;
Palladium Adatoms On Gold Nanoparticles As Electrocatalysts For Ethanol Electro-Oxidation In Alkaline Solutions, Hui-Mei Chen, Shang-Qian Zhu, Jia-Le Huang, Min-Hua Shao
Journal of Electrochemistry
Palladium (Pd) is a good catalyst for ethanol electro-oxidation in alkaline solutions. The activity of Pd is further improved in this study by modifying the gold (Au) nanoparticles with Pd adatoms using a simple spontaneous deposition process. The Pd overlayer on the Au core (Au@Pd) is un-uniform with some Au atoms exposed to the electrolyte. The activity of Au@Pd/C toward ethanol oxidation reaction (EOR) is much higher than that of Pd/C in an alkaline solution. The peak current density of Au@Pd/C is 4.6 times higher than that of Pd/C with a 100 mV lower onset potential. The enhanced activity may …
Fuel Cells Reactor For Chemicals And Electric Energy Cogeneration,
2018
Shanghai Electrochemical Energy Devices Research Center, Department of Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China;
Fuel Cells Reactor For Chemicals And Electric Energy Cogeneration, Zhi-Lin Heng, Xiao-Zi Yuan, Yi-Mei Yin, Zi-Feng Ma
Journal of Electrochemistry
As an energy conversion device, fuel cells can efficiently convert chemical energy into electrical energy. With the developing of technology, it is used as a reactor to conduct the synthesis of high value-added chemicals while generating electrical energy. Having benefits such as mild reaction conditions, controllability of the reaction process, high selectivity of the product, as well as high efficiency of energy utilization, it is widely used in many fields such as preparation of high value-added industrial products, gas separation, water treatment, etc. This paper introduces the current trends and statuses of fuel cell reactors in the cogeneration of chemicals …
