Synthesis, Characterisation And Catalytic Evaluation Of Castor Oil-Templated Mesoporous Sulfated Solid Acid Catalysts For Esterification Reaction,
2022
Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, Dar es Salaam
Synthesis, Characterisation And Catalytic Evaluation Of Castor Oil-Templated Mesoporous Sulfated Solid Acid Catalysts For Esterification Reaction, Steven Nyandoro Pr
Tanzania Journal of Engineering and Technology (TJET)
In bio-refinery and other catalytic reactions, heterogeneous catalysts confer advantage over homogenous catalysts due to minimized recovery and separation costs. However, templating surfactant and solid support for the synthesis of heterogeneous catalysts ought to consider their cheap sources and environmentally friendliness for their sustainable use. Thus, with the vision to make the process significantly benign, in the present work, solid acids were synthesised from renewable sources (castor oil as surfactant and rice husk as the source of silica). The synthesised castor oil-templated mesoporous sulfonic acid modified catalysts (SO3H-MTS and SO3H-MT-RHS) were characterised and evaluated for catalytic esterification of acetic acid …
Optimization Of Pulsed Laser Deposition Parameters For Single Crystalline (011) Oriented Tetragonal Pzt Thin Films,
2022
University of Dar es salaam
Optimization Of Pulsed Laser Deposition Parameters For Single Crystalline (011) Oriented Tetragonal Pzt Thin Films, Mahamudu H. Mtebwa
Tanzania Journal of Engineering and Technology (TJET)
Recent advances in nanotechnology applications require the processing of high-quality thin films. A systematic study of the optimization of Pulsed deposition parameters for (110) oriented tetragonal PZT thin films is reported in this work. Prior to film deposition, a highly tetragonal Pb(Zr0.5, Ti0.95) or PZT 05/95 was selected to be deposited on (110) oriented Strontium titanate, SrTiO3 substrate, STO(110) to insure small compressive misfit strain. Unlike SRO, the LSOM bottom electrode was then successfully grown at 620 °C, 1.0 J/cm2 and a target-substrate distance of 3.9 cm. Finally, deposition parameters of PZT were progressively optimized through monitoring film morphological changes. …
Properties Of (Cd, Zn)S Films Deposited By Dc Co-Sputtering,
2022
Department of Physics, Materials Science and Solar Energy Group, University of Dar es Salaam, Dar es Salaam, Tanzania
Properties Of (Cd, Zn)S Films Deposited By Dc Co-Sputtering, Lwitiko P. Mwakyusa
Tanzania Journal of Engineering and Technology (TJET)
CdS thin film is commonly used as a buffer layer in most thin film solar cells. However, the buffer layer with less absorption in the visible region of the solar spectrum as well as that which provides perfect lattice matching with the absorbers is required. The incorporation of Zn in the CdS films can affect the structural and optical properties of the buffer layer. In this work, films of CdS and (Cd,Zn)S films were deposited by DC sputtering utilizing CdS and Zn targets. The concentration of Zn in the CdS was varied by changing the sputtering power of the Zn …
Lead Acid Battery Recycling In The Current Tanzania Industrialization Drive: Challenges And Opportunities,
2022
University of Dar es salaam
Lead Acid Battery Recycling In The Current Tanzania Industrialization Drive: Challenges And Opportunities, Divina D. Kaombe
Tanzania Journal of Engineering and Technology (TJET)
ABSTRACT Advancements in automotive technologies, Information and Communications Technology and renewable energy technologies have increased the use of lead acid batteries as a source of portable and rechargeable energy. This has considerably increased the number of spent batteries with adverse effects on the environment and human health; which calls for recycling of spent batteries. This work was conducted to investigate challenges facing the formal business of recycling spent batteries and potential manufacturers of new lead-acid batteries in Tanzania. The work involved collection of information from key stakeholders such as collectors, dealers, Tanzania Revenue Authority and recyclers. It was found out …
A Chemical Study Of Archaeometallurgical Ceramics From Southwestern Tanzania,
2022
Department of Archaeology and Heritage Studies, College of Humanities, University of Dar es Salaam, Dar es Salaam
A Chemical Study Of Archaeometallurgical Ceramics From Southwestern Tanzania, Edwinus Lyaya
Tanzania Journal of Engineering and Technology (TJET)
Archaeometallurgical ceramics, including furnaces, tuyères, and potteries, were required for successful pre-industrial iron smelting and refining. However, there are limited chemical studies on archaeometallurgical ceramics in Tanzania. This paper examined the nature of clay source in terms of refractoriness, determined whether there were multiple clay sources, and verified the refractoriness of the archaeometallurgical ceramics. An x-ray fluorescence (XRF) analytical technique and experimental re-firing of the archaeometallurgical ceramics were employed. The chemical data clustered in the mullite region on the Al2O3-SiO2-FeO ternary system indicate that iron smelters and refiners chose refractory clay sources for making archaeometallurgical ceramics. Small range and standard …
Determination Of Effectiveness Of Combined Biological And Physicochemical Treatment Of Vinasse,
2022
Department of Chemical and Processing Engineering, University of Dar es Salaam, Dar es Salaam
Determination Of Effectiveness Of Combined Biological And Physicochemical Treatment Of Vinasse, Mahir Mohammed Said
Tanzania Journal of Engineering and Technology (TJET)
Combined biological and Physicochemical treatment method was used to treat vinasse using microorganisms (Aspergillus niger (fungi) and Bacillus subtilis (bacteria)), coagulants (aluminium sulphate (Al2(SO4)3) and iron III chlorides (FeCl3)) and followed by filtration. Three factors; coagulant type, type of microorganism and coagulant concentration was analysed using full factorial design (2n) with replication, on their percentage removal of Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solids (TSS) and turbidity. Pareto chart and regression analysis with a 95% confidence interval (5% significant level) were used to analyse the results using MINITAB 22 (current version). Initially, the vinasse had (COD), …
Synthesis And Characterization Of Hybrid Catalysts For Fischer-Tropsch Jet Fuel Production,
2022
Georgia Southern University
Synthesis And Characterization Of Hybrid Catalysts For Fischer-Tropsch Jet Fuel Production, Jack M. Steinagel
Honors College Theses
Climate change is a major issue that our world is facing today. Finding renewable options for current infrastructure is paramount to solving this issue. Fischer-Tropsch synthesis of syngas from gasified biomass can produce renewable fuels that can be used in current conventional combustion engines. In order to make this process more industrially viable, a higher selectivity towards the desired range of liquid hydrocarbon products must be achieved. A novel way to do this is to introduce a catalyst to the Fischer-Tropsch reaction. The catalyst’s physical and chemical properties can promote chain growth of specific hydrocarbons. For the purpose of this …
Synthesis Of Novel Chiral Phosphorothioic Acid Organocatalysts And Application To Synthetic Methodology,
2022
University of Nevada, Las Vegas
Synthesis Of Novel Chiral Phosphorothioic Acid Organocatalysts And Application To Synthetic Methodology, Parsa Azaei
Undergraduate Research Symposium Posters
Much research efforts have been centered towards the synthesis of novel Bronsted acid catalysts. These organocatalyst enable synthesis of natural products, pharmaceuticals, and bioactive small molecules under toxic-metal-free conditions by donating their protons, while not being consumed in the reaction. Chiral phosphorothioic acid have significant potential as novel organocatalysts due to their high modifiability of chirality and acidity under environmentally friendly conditions; however, synthesis of these organocatalysts are far and in between. Therefore, our research aimed to i) synthesize novel phosphorothioic acid organocatalysts and ii) to apply these novel catalysts toward new methodology development.
Elucidation Of Active Site And Mechanism Of Metal Catalysts Supported In Nu-1000,
2022
Clemson University
Elucidation Of Active Site And Mechanism Of Metal Catalysts Supported In Nu-1000, Hafeera Shabbir
All Dissertations
Advances in extraction of shale oil and gas has increased the production of geographically stranded natural gas (primarily consisting of methane (C1) and ethane (C2)) that is burned on site. A potential utilization strategy for shale gas is to convert it into fuel range hydrocarbons by catalytic dehydrogenation followed by oligomerization by direct efficient catalysts. This work focuses on understanding metal cation catalysts supported on metal-organic framework (MOF) NU-1000 that will actively and selectively do this transformation under mild reaction conditions, while remaining stable to deactivation (via metal agglomeration or sintering). I built computational models validated by experimental methods to …
Insight Into The Effects Of Cation Disorder And Surface Chemical Residues On The Initial Coulombic Efficiency Of Layered Oxide Cathode,
2022
1. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, P. R. China;2. China National Quality Supervision Testing Center for Industrial Explosive Materials, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu P.R. China;
Insight Into The Effects Of Cation Disorder And Surface Chemical Residues On The Initial Coulombic Efficiency Of Layered Oxide Cathode, Jin-Li Liu, Han-Feng Wu, Zhi-Bei Liu, Ying-Qiang Wu, Li Wang, Feng-Li Bei, Xiang-Ming He
Journal of Electrochemistry
Lithium layered oxide LiNi0.6Co0.2Mn0.2O2 (NCM622) is one of the most promising cathode materials in high-energy lithium-ion batteries for electric vehicles. However, one drawback for NCM622 is that its initial coulombic efficiency (ICE) is only about 87%, which is at least 6% lower than that of LiCoO2 or LiFePO4. In this work, we investigated the effects of surface chemical residues (e.g., LiOH and Li2CO3) and Li/Ni cation disorder resulted during the sintering on the ICE. We found that the ICE of the as-prepared samples could be boosted …
Electrochemical Syntheses Of Nanomaterials And Small Molecules For Electrolytic Hydrogen Production,
2022
School of Materials Science and Engineering, Nanyang Technological University,50 Nanyang Avenue, Singapore, 639798, Singapore;
Electrochemical Syntheses Of Nanomaterials And Small Molecules For Electrolytic Hydrogen Production, Jia-Qi Wei, Xiao-Dong Chen, Shu-Zhou Li
Journal of Electrochemistry
Hydrogen is a clean, efficient, renewable energy resource and the most promising alternative to fossil fuels for future carbon-neutral energy supply. Therefore, sustainable hydrogen production is highly attractive and urgently demanded, especially via water electrolysis that has clean, abundant precursors and zero emission. However, current water electrolysis is hindered by the sluggish kinetics and low cost/energy efficiency of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this regard, electrochemical synthesis offers prospects to raise the efficiency and benefit of water electrolysis by fabricating advanced electrocatalysts and providing more efficient/value-adding co-electrolysis alternatives. It is an eco-friendly and facile …
Alkaline Water Electrolysis For Efficient Hydrogen Production,
2022
State Key Laboratory of Chemical Resource Engineering, College of Chemistry,Beijing University of Chemical Technology, Beijing 100029, China;
Alkaline Water Electrolysis For Efficient Hydrogen Production, Wen-Fu Xie, Ming-Fei Shao
Journal of Electrochemistry
Hydrogen production from water electrolysis is a sustainable and environmentally benign strategy in comparison with fossil fuel-based hydrogen. However, this promising technique suffers from the high energy consumption and unsatisfactory cost due to the sluggish kinetics of both half reaction and inferior stability of electrocatalysts. To address this challenge, herein, we present a timely and comprehensive review on advances in alkaline water electrolysis that is already commercialized for large scale hydrogen production. The design principles and strategies with aiming to promote the performance of hydrogen generation are discussed from the view of electrocatalyst, electrode, reaction and system. The challenges and …
Alkaline Seawater Electrolysis At Industrial Level:Recent Progress And Perspective,
2022
1. School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link,Singapore 637371, Singapore;
Alkaline Seawater Electrolysis At Industrial Level:Recent Progress And Perspective, Tao Zhang, Yi-Pu Liu, Qi-Tong Ye, Hong-Jin Fan
Journal of Electrochemistry
Industrial hydrogen generation through water splitting, powered by renewable energy such as solar, wind and marine, paves a potential way for energy and environment sustainability. However, state-of-the-art electrolysis using high purity water as hydrogen source at an industrial level would bring about crisis of freshwater resource. Seawater splitting provides a practical path to solve potable water shortage, but still faces great challenges for large-scale industrial operation. Here we summarize recent developments in seawater splitting, covering general mechanisms, design criteria for electrodes, and industrial electrolyzer for direct seawater splitting. Multi-objective optimization methods to address the key challenges of active sites, reaction …
A Self-Supported Ru-Cu3P Catalyst Toward Alkaline Hydrogen Evolution,
2022
New Energy Research Institute, School of Environment and Energy, South China University of Technology, Higher Education Mega Center, Guangzhou 510006, Guangdong, China;
A Self-Supported Ru-Cu3P Catalyst Toward Alkaline Hydrogen Evolution, Zi-Xuan Wan, Chao-Hui Wang, Xiong-Wu Kang
Journal of Electrochemistry
Transition metal phosphide (TMP) is a kind of effective catalysts toward hydrogen evolution reaction (HER) in alkaline electrolytes. However, the performance of TMP catalysts is strongly limited by water splitting. In this work, we developed a method to prepare a copper foam (CF) supported Ru-doped Cu3P catalyst (Ru-Cu3P/CF) by a consecutive growth of Cu(OH)2 nanoarrays, soaking in RuCl3 solution and phosphorization. A large surface area was obtained by the self-supported catalysts with the appropriative Ru doping. As an excellent HER catalyst, it exhibited a low overpotential of 95.6 mV at a current density of …
Catalytic Effect Of Disordered Ru-O Configurations For Electrochemical Hydrogen Evolution,
2022
1. MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, Harbin Institute of Technology, Harbin, 150001, China;2. Chongqing Research Institute of HIT, Chongqing 401135, P. R. China;
Catalytic Effect Of Disordered Ru-O Configurations For Electrochemical Hydrogen Evolution, Xue Sun, Ya-Jie Song, Ren-Long Li, Jia-Jun Wang
Journal of Electrochemistry
Phase engineering is considered as an effective method for modulating the electronic structure and catalytic activity of catalysts. The disordered conformation of amorphous materials allows flexible reforming of the surface electronic structure, showing their attractiveness as catalysts for hydrogen evolution reaction (HER). Herein, we designed and developed an amorphous ruthenium dioxide (a-RuO2) catalyst with a disordered Ru-O configuration. The conformational relationship between Ru-O ordering and HER performance is established by combining advanced electron microscopic techniques with detailed electrochemical tests. Specifically, the disordered Ru-O coordination significantly enhanced the HER catalytic activity in both acidic and alkaline media, ultimately leading …
Élimination Des Vapeurs Toxiques Par Oxydation : Développement De Procédures D'Évaluation Des Systèmes De Purification De L'Air Des Conduits De Ventilation,
2022
Concordia University
Élimination Des Vapeurs Toxiques Par Oxydation : Développement De Procédures D'Évaluation Des Systèmes De Purification De L'Air Des Conduits De Ventilation, Chang-Seo Lee, Fariborz Haghighat, Alireza Haghighat Mamaghani, Zahra Shayegan, Ali Bahloul, Mélanie Huard, Lexuan Zhong, Mitra Bahr
Rapports de recherche scientifique
L'exposition à des composés organiques volatils (COV) dans les lieux de travail peut avoir des effets aigus, notamment sous forme d'irritation de la peau, des yeux, de la bouche et du nez. Certains produits peuvent également provoquer des effets chroniques, comme l'asthme et le cancer. La prévention de tels effets nocifs sur la santé des travailleurs par l'adoption et la mise en œuvre de mesures visant à en éliminer ou à tout le moins réduire le risque s'avère importante. Parmi les approches développées à ce jour pour réduire l'exposition aux polluants de l'air intérieur – dont les COV –, la …
Removal Of Toxic Vapors By Oxidation: Development Of Laboratory Test Procedures For In-Duct Air Cleaning Systems,
2022
Concordia University
Removal Of Toxic Vapors By Oxidation: Development Of Laboratory Test Procedures For In-Duct Air Cleaning Systems, Chang-Seo Lee, Fariborz Haghighat, Alireza Haghighat Mamaghani, Zahra Shayegan, Ali Bahloul, Mélanie Huard, Lexuan Zhong, Mitra Bahr
Rapports de recherche scientifique
L'exposition à des composés organiques volatils (COV) dans les lieux de travail peut avoir des effets aigus, notamment sous forme d'irritation de la peau, des yeux, de la bouche et du nez. Certains produits peuvent également provoquer des effets chroniques, comme l'asthme et le cancer. La prévention de tels effets nocifs sur la santé des travailleurs par l'adoption et la mise en œuvre de mesures visant à en éliminer ou à tout le moins réduire le risque s'avère importante. Parmi les approches développées à ce jour pour réduire l'exposition aux polluants de l'air intérieur – dont les COV –, la …
Preface To Special Issue On Water Electrolysis For Hydrogen Production,
2022
1. School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044;
Preface To Special Issue On Water Electrolysis For Hydrogen Production, Li Li, Jin-Song Hu, Zi-Dong Wei
Journal of Electrochemistry
No abstract provided.
The Rapid Preparation Of Efficient Mofeco-Based Bifunctional Electrocatalysts Via Joule Heating For Overall Water Splitting,
2022
1. Fuel Cell System and Engineering Laboratory, Key Laboratory of Fuel Cells & Hybrid Power Sources, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China;2. University of Chinese Academy of Sciences, Beijing, 100049, China;
The Rapid Preparation Of Efficient Mofeco-Based Bifunctional Electrocatalysts Via Joule Heating For Overall Water Splitting, Ao Zhou, Wei-Jian Guo, Yue-Qing Wang, Jin-Tao Zhang
Journal of Electrochemistry
Water electrolysis is an available way to obtain green hydrogen. The development of highly efficient electrocatalysts is a current research hotspot for water splitting, but it remains challenging. Herein, we demonstrate the synthesis of a robust bifunctional multi-metal electrocatalysts toward water splitting via the rapid Joule-heating conversion of metal precursors. The composition and morphology were well regulated via altering the ratio of metal precursors. In particular, the trimetal MoC/FeO/CoO/carbon cloth (CC) electrode revealed the outstanding bifunctional electrocatalytic performance due to the unique composition and large electrochemical active surface area. Typically, the MoC/FeO/CoO/CC catalyst needed low overpotentials of 121 and 268 …
Surface Structure Engineering Of Feni-Based Pre-Catalyst For Oxygen Evolution Reaction: A Mini Review,
2022
1. State Key Laboratory of Electroanalytic Chemistry, Jilin Province Key Laboratory of Low Carbon Chemistry Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences,Changchun 130022, China;2. School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China;
Surface Structure Engineering Of Feni-Based Pre-Catalyst For Oxygen Evolution Reaction: A Mini Review, Jia-Xin Li, Li-Gang Feng
Journal of Electrochemistry
Nitrite, a widespread raw material, is harmful to human health for long-term consumption. At present, the detection methods of nitrite mainly include chemical analysis, fluorescence, ultraviolet spectrophotometry and chromatography. These methods have ideal sensitivity and selectivity, but also have some characteristics: cumbersome operation, expensive equipment and professional personnel. Therefore, the development of a simple and sensitive nitrite assay is of great significance. In this paper, the Au/rGO/FeOOH composite materials, which revealed good synergistic catalytic performance among the three elements in the composite, were prepared by simple hydrothermal method and reduction method for the first time with large specific surface area …
