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three-way-catalyst
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Modification of Three-Way Catalyst (Twc)Formulation for Gasoline Vehicles with the Goal of Improving Its Thermal Stability
, M.Sc. Thesis Sharif University of Technology ; Hamzehlouyan, Tayebeh (Supervisor)
Abstract
Vehicle exhaust gas catalysts play a significant role in air pollution control. In order to solve the problems of cold start and limited supply of precious metals, new studies have focused on the development of three-way catalysts for gasoline vehicles with small amounts of precious metals and increase thermal stability. Different metal ions, especially rare earth metals, due to different physical and chemical properties, show different reinforcing effects on the properties of ceria-zirconia-based materials. Previous studies have shown that the enhancing effect of these materials and the ceria-zirconia ratio on catalyst activity and stability, as well as studies on thermal stability at 1050...
Examination of Activity of Three-Way Catalysts Toward CO and Hydrocarbon Emission Reduction from Tehran Gasoline Taxis
, M.Sc. Thesis Sharif University of Technology ; Hamzehlouyan, Tayebeh (Supervisor) ; Hosseini, Vahid (Co-Supervisor)
Abstract
Air pollution is one of the main environmental problems in Iran's metropolises, especially in the city of Tehran. Taxis have a significant contribution to pollution due to the long distances they travel during the day. Due to the fact that the operation of automotive three-way catalysts is a function of their operating conditions, and considering the different fuel composition in Iran and the specific conditions of engine performance, exhaust gas composition can be different from similar cases abroad. A commercial three-way catalyst was tested to evaluate its performance under conditions relevant to the exhaust gas of Tehran's taxis fleet. In this study, CO and C3H6 were considered as the...
Synthesis and Evaluation of a Three-Way Catalyst for CO, Hydrocarbon and Nitrogen Oxide Emission Control in CNG-Fueled Vehicles
, M.Sc. Thesis Sharif University of Technology ; Hamzehlouyan, Tayebeh (Supervisor)
Abstract
According to the reports of the Tehran Air Quality Control Company, mobile sources are responsible for the emission of 70-85% of air pollutant in this metropolis. Over the past decades, compressed natural gas (CNG) is known as a cleaner fuel and a suitable alternative to gasoline and diesel fuels in the transportation section in some countries. However, methane emissions from natural gas vehicles is a significant challenge because it is a potent greenhouse gas and plays important role in global warming. In addition, because of another pollutant emissions from these vehicles, exhaust gas treatment is a crucial issue. Using Three-Way catalysts (TWC) is the conventional method in order to...