Catalysis and Reaction Engineering Commons^™

Determination Of The Kinetic Parameters Of Cholesterol Oxidation Using Cholesterol Oxidase From Streptomyces Sp., Meka Saima Perdani, Heri Hermansyah, Muhamad Sahlan, Dwini Normayulisa Putri, Teguh Pambudi, Anggi Khairina Hanum Hasibuan

Makara Journal of Technology

Cholesterol oxidase (CO) was successfully produced from Streptomyces sp. via the submerged fermentation method, and 69 U/mL enzyme activity was obtained. This study aimed to determine cholesterol oxidation kinetics and the production of CO as a catalyst. The enzyme was diluted to 0.15, 0.075, and 0.00375 U/mL for the oxidation reaction. The substrate was also prepared in three concentrations: 3.23, 6.46, and 12.93 mM. The optimization of conditions for enzymatic cholesterol oxidation was investigated through measurement of the effect of initial cholesterol and enzyme concentrations. Cholesterol concentration was rapidly measured via high-performance liquid chromatography (HPLC). The kinetics of CO were …

Predictive Modeling And Sustainability Assessment Of Hydrothermal Liquefaction Of Seaweeds: A Techno-Economic And Life Cycle Analysis Approach, Micheal O. Asama

Mechanical Engineering Theses

This study presents comprehensive predictive models and an economic and environmental assessment of HTL for converting macroalgae into biofuels and valuable co-products. Predictive models were developed based on experimental kinetic data to simulate batch HTL of brown seaweed, capturing the yields of biocrude, gas, biochar, and water-soluble compounds as functions of key process variables, including temperature, time, pressure, and water-to-biomass ratio. Analysis of Variance (ANOVA) confirmed that temperature and residence time significantly affect biocrude yield, with an optimal yield of 23% achieved at 283°C, 200 bar, 54 minutes, and a 10:1 water-to-biomass ratio. The model’s predictive accuracy was validated with …

Synthesis, Characterization And Testing Of Graphene-Based Materials For Proton-Exchange Membrane Fuel Cell Catalysts, Hassan Shirzadi Jahromi

Dissertations

The requirement for low cost and efficient catalysts for fuel cells motivated the proposed research on Nitrogen-doped reduced graphene oxide (N-rGO) integrated with transition metal zeolitic imidazolate frameworks (ZIFs). Synthesis, characterization and performance evaluation of the newly synthesized nitrogen-doped graphene oxide-based catalysts for Proton Exchange Membrane Fuel Cells (PEMFCs) constitutes the main objective of this thesis.

The synthesis of N-rGO combined with cobalt, nickel, or iron ZIFs was carried out using wet chemical methods followed by one step pyrolysis at 900°C, resulting in catalysts with highly porous structures and uniform metal nanoparticle distribution. These were characterized for structure, microstructure, composition …

Development And Characterization Of Organic Electrocatalysts For Use In Zinc-Air Batteries, Christopher John Merkel

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

The global deployment of solar photovoltaic and wind power is projected by the International Energy Agency as the primary pathway to reduce dependence on fossil fuels. However, these technologies face a critical bottleneck: their inherently intermittent power generation. For “intermittent renewables” to become the dominant source of electrical energy, efficient energy storage systems are essential. Current storage solutions are not viable on a global scale due to material scarcity, safety concerns, and high capital costs. Among emerging technologies, zinc-air batteries (ZABs) have garnered significant interest. ZABs offer a theoretical energy density five times greater than traditional lithium-ion batteries, utilize safe …

Regulating Cox Conversion Through Catalyst Design And Reaction Energy Input, Ewa Chukwu

All Dissertations

Carbon dioxide (CO₂) emissions, primarily from fossil fuel use in energy and chemical production, are the leading driver of global warming. The chemical industry is the third-largest source of these emissions, so reducing its carbon footprint—and ultimately achieving “CO₂ emissions-free” chemical manufacturing—is critical to combating global warming. Thermal catalysis is the workhorse of industrial chemical manufacturing, generating CO₂ emissions from two main sources: the actual chemical transformations of fossil feedstocks and burning of fossil fuels to provide the process heat. Therefore, developing and implementing technologies to mitigate the carbon emissions associated with these emissions sources is essential for decarbonizing the …

Nickel Electrocatalysts On Carbon Supports For The Hydrogen Evolution Reaction., Mohan Paudel

Electronic Theses and Dissertations

Hydrogen is an important energy storage alternative to fossil fuels due to its high energy density. Currently, most hydrogen is produced through petroleum feedstocks, which produce large amounts of carbon dioxide. However, a more eco-friendly method is the electrocatalytic splitting of water into hydrogen and oxygen. Efficient catalysts for the hydrogen evolution reaction (HER) are typically platinum group metals, which are rare and expensive. There is growing interest in developing HER electrocatalysts with earth-abundant metals for water electrolysis. Nickel, which lies in the same group in the periodic table as Pt and has similar chemical properties, is explored extensively for …

The 9th National Conference Of Solid State Battery Successfully Held In Xiamen, Fujian, Zheng-Liang Gong

Journal of Electrochemistry

No abstract provided.

The Award Ceremony Of The 2nd Xiamen University Short Video Abstract Contest For Science And Technology Journal Papers Came To A Successful Conclusion, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Journal Of Electrochemistry, The Flagship Journal Of Chinese Chemical Society Electrochemical Committee, Made A Public Appearance At The 22nd National Electrochemical Congress, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Single Nanobubble Formation On Au Nanoelectrodes And Au@Ws2 Nanoelectrodes: Voltammetric Analysis And Electrocatalysis, Xian-Zhun Luo, Xiao-Hu Chen, Yong-Xin Li

Journal of Electrochemistry

Taking advantage of the extremely small size of the gold nanodisk electrode, the single hydrogen nanobubble generated on the surface of the nanoelectrode was studied to evaluate its hydrogen evolution performance. It was found that compared with the bare gold nanodisk electrode, the bubble formation potential of the gold nanodisk electrode modified with tungsten disulfide quantum dots (WS₂ QDs) on the surface was more positive, indicating that its hydrogen evolution activity was higher. Microdynamic model analysis shows that the average standard rate constant of the rate-determining step of the hydrogen evolution reaction of gold nanoelectrodes modified with WS_{2 …}

The Adviser Of Journal Of Electrochemistry Professor Christian Amatore Received The Chinese Government Friendship Award, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Goodbye With Tears! Deep Condolences To Academician Zhao-Wu Tian!, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Journal Of Electrochemistry Is Selected To Entering Ici Journals Master List, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Efficient Phosphate Removal From Water Using Ductile Cast Iron Waste: A Response Surface Methodology Approach, Mai Hassan Dr., Nada Alkhashab Eng., Ahmed Osman Dr., Dalia A. Ali Eng

Chemical Engineering

Water scarcity is a critical issue worldwide. This study explores a novel method for addressing this issue by using ductile cast iron (DCI) solid waste as an adsorbent for phosphate ions, supporting the circular economy in water remediation. The solid waste was characterized using XRD, XRF, FTIR, and particle size distribution. Wastewater samples of different phosphate ion concentrations are prepared, and the solid waste is used as an adsorbent to adsorb phosphate ions using different adsorbent doses and process time. The removal percentage is attained through spectrophotometer analysis and experimental results are optimized to get the optimum conditions using Design …

Electronic Communication Between Co And Ru Sites Decorated On Nitrogen-Doped Carbon Nanotubes Boost The Alkaline Hydrogen Evolution Reaction, Meng-Ting Gao, Ying Wei, Xue-Meng Hu, Wenj-Jie Zhu, Qing-Qing Liu, Jin-Yuan Qiang, Wan-Wan Liu, Ying Wang, Xu Li, Jian-Feng Huang, Yong-Qiang Feng

Journal of Electrochemistry

Designing highly efficient Pt-free electrocatalysts with low overpotential for an alkaline hydrogen evolution reaction (HER) remains a significant challenge. Here, a novel and efficient cobalt (Co), ruthenium (Ru) bimetallic electrocatalyst composed of CoRu nanoalloy decorated on the N-doped carbon nanotubes (CoRu@N-CNTs), was prepared by reacting fullerenol with melamine via hydrothermal treatment and followed by pyrolysis. Benefiting from the electronic communication between Co and Ru sites, the as-obtained CoRu@N-CNTs catalyst exhibited superior electrocatalytic HER activity. To deliver a current density of 10 mA·cm^–2, it required an overpotential of merely 19 mV along with a Tafel slope of 26.19 mV·dec …

Zhong-Qun Tian, Academician And Honorary Member Of Electrochemistry Committee Chinese Chemical Society, Achieved "Raman Lifetime Award", Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

2024 Tianmulake Advanced Anode Materials Innovation Forum And Sixth National Conference Of Advanced Battery Failure Analysis And Testing Technology Concluded Successfully, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Chinese Chemical Society: First Young Scholars' Symposium On Electrosynthesis Held Successfully, Chinese Society Of Electrochemistry (Cse)

Journal of Electrochemistry

No abstract provided.

Immobilization Of Ni(Ii) On Amine-Functionalized Mesoporous Silica As Catalyst For Benzyl Alcohol Acetylation Reaction, Wardah Nabilah, Eko Sri Kunarti, Fajar Inggit Pambudi

Makara Journal of Science

In this study, amine-functionalized and Ni(II)-immobilized mesoporous silica materials were synthesized. This research aimed to synthesize mesoporous silica based on rice husk ash functionalized with amine and immobilized with Ni(II). The activity of amine-functionalized and Ni(II)-immobilized mesoporous silica materials was studied for the acetylation of benzyl alcohol with acetic anhydride as the acetylating agent. First, mesoporous silica was synthesized using rice husk ash using the sol–gel method, followed by amine functionalization using (3-aminopropyl)triethoxysilane (APTES) and Ni(II) immobilization through ultrasonic treatment. The results obtained showed that amine-functionalized and Ni(II)-immobilized mesoporous silica (SiO₂/APTES/Ni(II)) were successfully synthesized, confirmed by Fourier transform …

Recent Advances On Ruthenium-Based Electrocatalysts For Lithium-Oxygen Batteries, Yu-Zhe Wang, Zhuo-Liang Jiang, Bo Wen, Yao-Hui Huang, Fu-Jun Li

Journal of Electrochemistry

Rechargeable lithium-oxygen (Li-O₂) batteries have attracted wide attention due to their high energy density. However, the sluggish cathode kinetics results in high overvoltage and poor cycling performance. Ruthenium (Ru)-based electrocatalysts have been demonstrated to be promising cathode catalysts to promote oxygen evolution reaction (OER). It facilitates decomposition of lithium peroxide (Li₂O₂) by adjusting Li₂O₂ morphologies, which is due to the strong interaction between Ru-based catalyst and superoxide anion (O₂^–) intermediate. In this review, the design strategies of Ru-based electrocatalysts are introduced to enhance their OER catalytic kinetics in …