Engineering Commons^™

Electrocatalytic “Volcano-Type” Effect Of Nano-Tio2 (A)/(R) Phase Content In Pt/Tio2-CnX Catalyst, Ai-Lin Cui, Yang Bai, Hong-Ying Yu, Hui-Min Meng

Journal of Electrochemistry

The relationship between the electrochemical activity of fuel cell catalysts and Pt particle size, as well as the catalyst support and co-catalyst is still unclear. In this work, FESEM, XRD, BET, TEM and CV techniques were adopted to investigate the effects of TiO₂ anatase (A)/rutile (R) phases content on the electrochemical activity of Pt electrocatalyst. The results showed that the anatase-rutile phase transformation occurred during the heat treatment of TiO₂ at 700 ~ 900 oC accompanied by the growth of two-phase crystalline size, and anatase was completely transformed into rutile at 900 oC. TEM results revealed that the …

Synthesis And Advanced Characterization Of Energy Materials, Erik Sarnello

Graduate Research Theses & Dissertations

Catalysts are used in an extremely broad range of systems including everything from biological systems to industrial processes. An ideal catalyst offers robust stability and high activity. This work focuses on the synthesis and characterization of materials that show promise in the field of catalysis. Advanced synchrotron characterization techniques and unique experimental design are highlighted to provide foundation work that will provide the necessary information to aid in designing and fabricating catalytic materials. Supported metal nanoparticle (SMN) catalysts are enormously crucial for many catalytic applications. However, catalyst deactivation, caused by sintering and coke formation, is a ubiquitous problem that significantly …

Dry Reforming Of Methane Using Microwave Irradiated Metal Oxide/Coal Char Catalysts, Anthony Carter

Graduate Theses, Dissertations, and Problem Reports

This research focuses on the synthesis of both shaped and amorphous powder materials, the combination of these materials with dried Powder River Basin (PRB) coal char, and their reactionary properties with methane and carbon dioxide gasses with conventional and microwave (MW) heating. The first goal of this project was to synthesize shaped micro and nano sized particles with ideal dielectric properties for converting electromagnetic energy into heat and proven capabilities of activating methane. These particles were synthesized via solvothermal, hydrothermal, and co-preceptory treatments alone and onto the surface of dried PRB coal char. PRB is a sub-bituminous, low-ranking coal (LRC) …

Nio@Rgo Supported Palladium And Silver Nanoparticles As Electrocatalysts For Oxygen Reduction Reaction, Shuo Yao, Tai-Zhong Huang, Rizwan Haider, Heng-Yi Fang, Jie-Mei Yu, Zhan-Kun Jiang, Dong Liang, Yue Sun, Xian-Xia Yuan

Journal of Electrochemistry

For pervasive applications of fuel cells, highly efficient and economical materials are required to replace Pt-based catalysts for oxygen reduction reaction (ORR). In this study, the NiO@rGO, Pd-NiO@rGO and Ag-NiO@rGO nanoparticles were synthesized, and their catalytic performances toward ORR were investigated. The results revealed that all the three materials were capable of catalyzing ORR, but both the Pd-NiO@rGO and Ag-NiO@rGO showed the better performances compared with the NiO@rGO in terms of the reaction pathway being 4-electron process, the increases of the onset potential and the intermediate yielding rate, as well as the extended stability. Moreover, the effect of Pd modification …

Extrusion Of Perovskite Oxide/ Silica Composites For Thermochemical Carbon Dioxide Conversion, Qian Li

USF Tampa Graduate Theses and Dissertations

In order to solve the increasing greenhouse effect problem, perovskite-type oxides have been used to convert CO2 to CO in a reverse water-gas shift chemical looping (RWGS-CL) process. Currently, the process is at the micro-reactor scale and used catalyst in powder form. However, formed materials are needed if the scale is to be increased.

Our research focus is on increasing the conversion yield of perovskite oxides with SiO2 support and scaling up the powder form perovskite-type oxides to pellet by extrusion. The binder added during the extrusion process must be removed to avoid affecting the performance of the catalyst and …

Influences Of Morphology And Nitrogen Doping On The Electrocatalytic Characteristics For Oxygen Reduction Reaction Of Nio/Rgo, Dong Liang, Heng-Yi Fang, Shuo Yao, Jie-Mei Yu, Zhao-Liang Zhang, Zhan-Kun Jiang, Xue-Ping Gao, Tai-Zhong Huang

Journal of Electrochemistry

In this research, the reduced graphene oxide (rGO) supported sheet-like NiO (NiO/rGO) and spherical-like NiO (NiO/N-rGO) catalysts for oxygen reduction reaction (ORR) were prepared. The structures, morphologies and chemical states of the two catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical catalytic performance of the two catalysts for ORR were investigated by cyclic voltammetry (CV), Tafel, linear sweeping voltammetry (LSV), rotating disc electrode (RDE) and rotating ring disc electrode (RRDE) tests. Electrochemical results showed that the current density and onset potential (about 0.89 V) …

Synthesis And Characterization Of LaXBa1-XFeYAl1-YO3, Perovskite Oxides, For Co2 To Co Conversion, Hanzhong Shi

USF Tampa Graduate Theses and Dissertations

As the greenhouse gas effect becomes more serious, it is important to find an effective way to reduce carbon dioxide emissions and/or convert it to value-added products. Based on the catalytic requirements, convert CO₂ to CO using perovskite-type oxides which are suitable for reverse water-gas shift chemical looping (RWGS-CL). The resulting carbon monoxide can be subsequently used for chemical energy storage in the form of hydrocarbon-based fuels and chemicals. This research focuses on the synthesis of the La_xBa_1-xFe_yAl_1-yO₃ perovskite-type oxides, which can form oxygen vacancies, or active sites for CO …

Method Of Increasing Mass Transfer Rate Of Acid Gas Scrubbing Solvents, Joseph E. Remias, Cameron A. Lippert, Kunlei Liu

Center for Applied Energy Research Faculty Patents

A method of increasing the overall mass transfer rate of acid gas scrubbing solids is disclosed. Various catalyst compounds for that purpose are also disclosed.

An Efficient Palladium-Thiourea Catalysed Heck Cross-Coupling Reaction For Molecular Electronic Interest, Wan M. Khairul, Mohd Shahrul Shahmi Md Shariff, Rafizah Rahamathullah, Adibah Izzati Daud, Mustaffa Shamsuddin, Siti Kamilah Che Soh

Makara Journal of Technology

The synthesis and utilization of C-C bonds formation are concerned about the key steps for the building of several conducting molecular electronics involving many asymmetric catalysts approached, which is an essential task that most researchers would ignore in preparing these materials to enhance the production yield of cross-coupling materials. Despite the enormous progress, there still remains a great demand for economic and practicable cross-coupling processes involving ultra-low catalyst loadings with high turnover numbers due to the employment of conventional metal catalyst. Thus, there has been an excessive interest to cultivate non-phosphine palladium catalysts for excellent achievement of activity, stability, and …

Materials Selection For Catalyst Supports, Connor G. Carr, Brianna L. Musicó, Andre Z. Shibata, Willie Kemp

Chancellor’s Honors Program Projects

No abstract provided.

Recycling Mf Solid Waste Into Mesoporous Nitrogen-Doped Carbon With Iron Carbide Complex In Graphitic Layers As An Efficient Catalyst For Oxygen Reduction Reaction, Can-Yun Zhao, Lin Huang, Yong You, Ying-Fang Yao, Xiao-Gang Su, Hong Wan, Jian-Guo Liu, Cong-Ping Wu

Journal of Electrochemistry

Nitrogen-doped carbon materials with iron ions are known as catalytic growth agents for the oxygen reduction reaction (ORR) in fuel cells, but the design and synthesis of high-performance and low-cost catalysts still remain a significant challenge. Herein, we present a cost-effective approach to dispose of MF solid waste as the precursor for the synthesis of MCFes catalyst with the favorable structure features such as the high specific surface area, abundant active sites and suitable pore structure. The results showed that the MCFe-10/10/2 had specific surface area as high as 780.7 m²•g^-1 and high efficient catalytic activity comparable …

Transition Metal Carbide (Tmc) Novel Materials For Novel Catalytic Applications, Svetlana Lagoykina

Open Access Theses & Dissertations

Transition metal carbides (TMC) constitute a diverse class of materials and traditionally have many technological applications. TMC became a subject of extensive research since 1973, when their platinum -like properties were discovered. They demonstrated high catalytical activity and selectivity in a variety of chemical reaction and have potential for some novel catalytic application.

This research is an effort to design new high effective, selective and stable bimetal or alkali promoted TMC catalyst. After extensive theoretical research a wide range of TMC, including bimetal and alkali promoted carbides, were synthesized by different methods. All solids were characterized by XRD and microscopy. …

Novel Nanostructures And Processes For Enhanced Catalysis Of Composite Solid Propellants, Robert Draper

Electronic Theses and Dissertations

The purpose of this study is to examine the burning behaviour of composite solid propellants (CSP) in the presence of nanoscale, heterogenous catalysts. The study targets the decomposition of ammonium perchlorate (AP) as a key component in the burning profile of these propellants, and seeks to identify parameters of AP decomposition reaction that can be affected by catalytic additives. The decomposition behavior of AP was studied in the presence of titanium dioxide nanoparticles in varying configurations, surface conditions, dopants, morphology, and synthesis parameters with the AP crystals. The catalytic nanoparticles were found to enhance the decomposition rate of the ammonium …

Green Diesel Production Via Catalytic Hydrogenation/Decarboxylation Of Triglycerides And Fatty Acids Of Vegetable Oil And Brown Grease, Elvan Sari

Wayne State University Dissertations

Increase in the petroleum prices, projected increases in the world’s energy demand and environmental awareness have shifted the research interest to the alternative fuel technologies. In particular, green diesel, vegetable oil/animal fat/waste oil and grease derived hydrocarbons in diesel boiling range, has become an attractive alternative to biodiesel— a mixture of fatty acid methyl esters, particularly due to its superior fuel properties that are similar to petroleum diesel. Hence, green diesel can be used as a drop-in fuel in the current diesel engines. The current technology for production of green diesel– hydrodeoxygenation of triglycerides and fatty acids over conventional hydrotreating …

Fabrication Of Horizontal Silicon Nanowires Using A Thin Aluminum Film As A Catalyst, Khaja Hafeezuddin Mohammed

Graduate Theses and Dissertations

Silicon nanowires have been the topic of research in recent years for their significant attention from the electronics industry to grow even smaller electronic devices. The semiconductor industry is built on silicon. Silicon nanowires can be the building blocks for future nanoelectronic devices. Various techniques have also been reported in fabricating the silicon nanowires. But most of the techniques reported, grow vertical silicon nanowires. In the semiconductor industry, integrated circuits are designed and fabricated in a horizontal architecture i.e. the device layout is flat compared to the substrate. When vertical silicon nanowires are introduced in the semiconductor industry, a whole …

Comparison Of Catalytic Performance On Different Materials Supported Pd Catalysts For Formic Acid Oxidation, Su-Dong Yang, Yan-Yu Liang, Zhu-Liang Wen, Qi-Jun Song, Xiao-Gang Zhang

Journal of Electrochemistry

Graphite oxide (GO) was prepared from by Hummers method. Then the graphene nanosheets supporting Pd catalysts were prepared by a single-step chemical reduction method. The electrocatalytic performance for formic acid oxidation of the prepared Pd/graphene composite was studied as an electrode material in comparison with the composite catalysts based on the other carbons (MWCNTs, SWCNTs, and Vulcan XC-72 carbon black). X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements indicated that the Pd nanoparticles were well dispersed on the surface of the graphene nanosheets with a small particle size. The electrocatalytic oxidation of formic acid was studied by electrochemically active …

Preparation And Electrocatalytic Activity Of The Pt/Wc/Tio2 Composites, Chun-An Ma, Bin Yu, Mei-Qin Shi, Xiao-Ling Lang

Journal of Electrochemistry

TiO2 was used as the support for preparation of Pt/WC/TiO2 composite catalyst. The composites were characterized by XRD, SEM and TEM methods. The electrocatalytical activity of Pt/WC/TiO2 composite for oxidation of methanol was investigated by cyclic voltammetry. Pt/WC/TiO2 exhibited higher activity compared with that of Pt/TiO2 and Pt/WC composite catalysts. Based on this we discussed the effects of crystal phases of TiO2 on the electrocatalytical activity of Pt/WC/TiO2 composite catalyst.

Influence Of Impurity Ions On Rice Husk Combustion, L Xiong, K Saito, E H. Sekiya, P Sujaridworakun, S Wada

Journal of Metals, Materials and Minerals

Rice husk (RH) contains various impurity ions such as K+ , Al3+, Fe3+, Mnn+ (n = 2 - 4), and P-containing acid ions. In the present work, some of their oxides, formed in RH combustion, were found to exert a strong influence on the middle- and late stages of RH combustion, and consequently, strongly affected the structure and properties of the final ash. Very recently, we proved for the first time that the existence of the transition metallic ions in rice husk can lead to a decrease of about 70°C in the terminal combustion temperature (Ttc) of RH. This catalytic …

Production Of Meso-And Giga-Porous Zirconia Particles—An Improved Multi-Step Particle Aggregation Process, Abhinandan Pattanayak

Abhinandan Pattanayak

No abstract provided.

High Temperature Wetting And Multilayer Adsorption In Oxide Systems, Haijun Qian

All Dissertations

The primary objective of this thesis research is to greatly advance the knowledge of the formation mechanism and thermodynamic stability of a unique class of surficial amorphous films (SAFs) and analogous intergranular films (IGFs) via critical experiments and modeling. These quasi-liquid IGFs and SAFs films exhibit the following distinct characteristics: 1) self-regulating (equilibrium) thicknesses on the order of 1 nm, 2) structures and compositions that are neither found nor stable as bulk phases, and 3) thermodynamic stability below the bulk solidus lines.
The first part of this study examines anisotropic wetting of ZnO single crystals by Bi2O3-rich liquid with and …

Oxygen Enrichment Effect Of Mno_2-Pt/C Compound Catalyst To The Cathode Of Pemfc, Hong-Feng Xu, Mao-Feng Zhang, Quan-Quan Gan, Cai-Sheng Huang

Journal of Electrochemistry

TO study of the oxygen storage material of air cathode is crucial for increasing performance of proton exchange membrane fuel cell.Using the MnO2 as oxygen storage materials,a MnO2-Pt/C catalysts were prepared and is used to replace the conventional Pt/C in air cathode.The electrochemical performance of air cathode composed of MnO2 supported on Pt/C and the properties of fuel cell composed of MnO2-Pt/C were investigated by using the CV,galvanostatic dischange method and TEM.

Investigation On The Resistance To Electrochemical Oxidation Of Carbon Nanotubes With Various Diameters, Yu-Yan Shao, Ge-Ping Yin, Yun-Zhi Gao, Peng-Fei Shi

Journal of Electrochemistry

The resistance to electrochemical oxidation of multi-wall carbon nanotubes(CNT) with various diameters is investigated by applying a fixed potential of 1.2 V(RHE) for 120 h in 0.5 mol L~(-1) H_(2)SO_(4).The oxidation current of CNTs decreases with their diameters,but CNTs between 10~20 nm in diameter(D1020) shows the lowest oxidation current.XPS analysis shows that,after oxidation,the increase in surface oxygen for D1020 is the smallest,implying that the oxidation degree for D1020 is the lowest.The conclusion can be reached that CNTs between 10~20 nm in diameter are the most resistant to electrochemical oxidation.The difference in electrochemical stability of CNTs is attributed to the difference …

Oxygen Enrichment Effect Of Ceo_2 To The Cathode Performance Of Proton Exchange Membrane Fuel Cell, Xiang-Li Hou, Hong-Feng Xu, Jian-Hua Dong, Xin Sun

Journal of Electrochemistry

CeO_2 was added to Pt/C catalyst in the cathode of PEMFC by both sol and impregnation methods.The samples were evaluated by TEM,cyclic voltammogram techniques and proton exchange membrane fuel cell performance test.The addition of CeO_2 obviously improved the performance of PEMFC and represented a notable function of oxygen enrichment in the cathode side.But with the addition of CeO_2,part of the catalyst surface was covered and led to the performance drop of the PEMFC.The best content of CeO_2 is 1% when it is added by impregnation method and 3% when it is added by sol method.