The Experts below are selected from a list of 239508 Experts worldwide ranked by ideXlab platform
Kui Jiao - One of the best experts on this subject based on the ideXlab platform.
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Catalytic hydrogen oxygen Reaction in anode and cathode for cold start of proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2015Co-Authors: Yueqi Luo, Kui Jiao, Bin Jia, Qing Du, Yan Yin, Huizhi Wang, Jin XuanAbstract:Abstract Fuel cell vehicles (FCVs) have shown the potential of commercialization in recent years. The concerns on the startup ability of proton exchange membrane (PEM) fuel cell stack from subfreezing temperature have risen. The hydrogen–oxygen Catalytic Reactions assisted cold start method is developed and analyzed in this study. It utilizes a small amount of hydrogen/air mixture to react at low temperature in the catalyst layers (CLs) through platinum catalyst. The interactions between this assisted method and various startup modes are the major issue to be discussed. Anode Catalytic Reaction with air mole fraction higher than 16% is effective to assist a 30-cell stack starting from −25 °C within 13 s in maximum power mode. However, cathode Catalytic Reaction cannot sustain a successful startup. The anode humidification effect plays an important role to reduce the stack resistance, and to increase the inherent heat generation rate. In maximum power mode and high current density constant power mode, anode Catalytic Reaction assisted cold start can be achieved within 10–20 s from −40 °C. Anode air mole fraction must be higher than 18% to ensure the successful cold start in these two modes. For constant power mode, the operating power must be lower than 12 W per cell. In constant current mode, when the current density is low, there would be less demand for anode Catalytic Reaction to achieve successful startup from −40 °C, indicating that lower current density operations have better survivability in low temperature. Nevertheless, much longer start duration is required for lower operating current. Generally, high current density operating mode with high air mole fraction is a more practical and energy efficient cold start strategy, as the startup time can be reduced significantly. Cold start from about −20 °C without ice accumulation is feasible using this method, which may have reduced concern about degradation. Increasing the volume of CL (porosity and thickness) also helps reduce the ice formation.
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modeling of assisted cold start processes with anode Catalytic hydrogen oxygen Reaction in proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2013Co-Authors: Qian Guo, Yueqi Luo, Kui JiaoAbstract:Abstract Catalytic hydrogen–oxygen Reaction is a potentially effective way to help start up proton exchange membrane fuel cells (PEMFCs) from sub-zero temperatures. In this study, the anode hydrogen–oxygen Catalytic Reaction is implemented in a three-dimensional multiphase cold start model. It is found that successful cold start from −20 °C can be achieved with the assist of the Catalytic Reaction in galvanostatic mode. With anode Catalytic Reaction, the start-up current density must be moderate, because a high current density lowers the assisted heating effect, and a low current density slows down the start-up process. The temperature difference between the anode and cathode catalyst layers (CLs) is negligible, which indicates that the heating location in the electrodes for the Catalytic Reaction makes no significant difference. The humidification of anode due to the Catalytic Reaction also reduces the ohmic resistance of the membrane, leading to enhanced performance during the start-up processes.
Yueqi Luo - One of the best experts on this subject based on the ideXlab platform.
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Catalytic hydrogen oxygen Reaction in anode and cathode for cold start of proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2015Co-Authors: Yueqi Luo, Kui Jiao, Bin Jia, Qing Du, Yan Yin, Huizhi Wang, Jin XuanAbstract:Abstract Fuel cell vehicles (FCVs) have shown the potential of commercialization in recent years. The concerns on the startup ability of proton exchange membrane (PEM) fuel cell stack from subfreezing temperature have risen. The hydrogen–oxygen Catalytic Reactions assisted cold start method is developed and analyzed in this study. It utilizes a small amount of hydrogen/air mixture to react at low temperature in the catalyst layers (CLs) through platinum catalyst. The interactions between this assisted method and various startup modes are the major issue to be discussed. Anode Catalytic Reaction with air mole fraction higher than 16% is effective to assist a 30-cell stack starting from −25 °C within 13 s in maximum power mode. However, cathode Catalytic Reaction cannot sustain a successful startup. The anode humidification effect plays an important role to reduce the stack resistance, and to increase the inherent heat generation rate. In maximum power mode and high current density constant power mode, anode Catalytic Reaction assisted cold start can be achieved within 10–20 s from −40 °C. Anode air mole fraction must be higher than 18% to ensure the successful cold start in these two modes. For constant power mode, the operating power must be lower than 12 W per cell. In constant current mode, when the current density is low, there would be less demand for anode Catalytic Reaction to achieve successful startup from −40 °C, indicating that lower current density operations have better survivability in low temperature. Nevertheless, much longer start duration is required for lower operating current. Generally, high current density operating mode with high air mole fraction is a more practical and energy efficient cold start strategy, as the startup time can be reduced significantly. Cold start from about −20 °C without ice accumulation is feasible using this method, which may have reduced concern about degradation. Increasing the volume of CL (porosity and thickness) also helps reduce the ice formation.
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modeling of assisted cold start processes with anode Catalytic hydrogen oxygen Reaction in proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2013Co-Authors: Qian Guo, Yueqi Luo, Kui JiaoAbstract:Abstract Catalytic hydrogen–oxygen Reaction is a potentially effective way to help start up proton exchange membrane fuel cells (PEMFCs) from sub-zero temperatures. In this study, the anode hydrogen–oxygen Catalytic Reaction is implemented in a three-dimensional multiphase cold start model. It is found that successful cold start from −20 °C can be achieved with the assist of the Catalytic Reaction in galvanostatic mode. With anode Catalytic Reaction, the start-up current density must be moderate, because a high current density lowers the assisted heating effect, and a low current density slows down the start-up process. The temperature difference between the anode and cathode catalyst layers (CLs) is negligible, which indicates that the heating location in the electrodes for the Catalytic Reaction makes no significant difference. The humidification of anode due to the Catalytic Reaction also reduces the ohmic resistance of the membrane, leading to enhanced performance during the start-up processes.
Jin Xuan - One of the best experts on this subject based on the ideXlab platform.
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Catalytic hydrogen oxygen Reaction in anode and cathode for cold start of proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2015Co-Authors: Yueqi Luo, Kui Jiao, Bin Jia, Qing Du, Yan Yin, Huizhi Wang, Jin XuanAbstract:Abstract Fuel cell vehicles (FCVs) have shown the potential of commercialization in recent years. The concerns on the startup ability of proton exchange membrane (PEM) fuel cell stack from subfreezing temperature have risen. The hydrogen–oxygen Catalytic Reactions assisted cold start method is developed and analyzed in this study. It utilizes a small amount of hydrogen/air mixture to react at low temperature in the catalyst layers (CLs) through platinum catalyst. The interactions between this assisted method and various startup modes are the major issue to be discussed. Anode Catalytic Reaction with air mole fraction higher than 16% is effective to assist a 30-cell stack starting from −25 °C within 13 s in maximum power mode. However, cathode Catalytic Reaction cannot sustain a successful startup. The anode humidification effect plays an important role to reduce the stack resistance, and to increase the inherent heat generation rate. In maximum power mode and high current density constant power mode, anode Catalytic Reaction assisted cold start can be achieved within 10–20 s from −40 °C. Anode air mole fraction must be higher than 18% to ensure the successful cold start in these two modes. For constant power mode, the operating power must be lower than 12 W per cell. In constant current mode, when the current density is low, there would be less demand for anode Catalytic Reaction to achieve successful startup from −40 °C, indicating that lower current density operations have better survivability in low temperature. Nevertheless, much longer start duration is required for lower operating current. Generally, high current density operating mode with high air mole fraction is a more practical and energy efficient cold start strategy, as the startup time can be reduced significantly. Cold start from about −20 °C without ice accumulation is feasible using this method, which may have reduced concern about degradation. Increasing the volume of CL (porosity and thickness) also helps reduce the ice formation.
Qian Guo - One of the best experts on this subject based on the ideXlab platform.
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modeling of assisted cold start processes with anode Catalytic hydrogen oxygen Reaction in proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2013Co-Authors: Qian Guo, Yueqi Luo, Kui JiaoAbstract:Abstract Catalytic hydrogen–oxygen Reaction is a potentially effective way to help start up proton exchange membrane fuel cells (PEMFCs) from sub-zero temperatures. In this study, the anode hydrogen–oxygen Catalytic Reaction is implemented in a three-dimensional multiphase cold start model. It is found that successful cold start from −20 °C can be achieved with the assist of the Catalytic Reaction in galvanostatic mode. With anode Catalytic Reaction, the start-up current density must be moderate, because a high current density lowers the assisted heating effect, and a low current density slows down the start-up process. The temperature difference between the anode and cathode catalyst layers (CLs) is negligible, which indicates that the heating location in the electrodes for the Catalytic Reaction makes no significant difference. The humidification of anode due to the Catalytic Reaction also reduces the ohmic resistance of the membrane, leading to enhanced performance during the start-up processes.
P Ray - One of the best experts on this subject based on the ideXlab platform.
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stationary inverted lyman population and a very stable novel hydride formed by a Catalytic Reaction of atomic hydrogen and certain catalysts
Optical Materials, 2004Co-Authors: R Mills, P RayAbstract:Abstract Rb+ to Rb2+ and 2K+ to K + K2+ each provide a Reaction with a net enthalpy equal to the potential energy of atomic hydrogen. The presence of these gaseous ions with thermally dissociated hydrogen formed a plasma having strong VUV emission with a stationary inverted Lyman population. We propose an energetic Catalytic Reaction involving a resonant energy transfer between hydrogen atoms and Rb+ or 2K+ to form a very stable novel hydride ion. Its predicted binding energy of 3.047 eV with the fine structure was observed at 4071 A, and its predicted bound-free hyperfine structure lines EHF=j23.00213×10−5+3.0563 eV (j is an integer) matched those observed for j=1–37 to within a 1 part per 104. This Catalytic Reaction may pump a cw H I laser.
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spectroscopic identification of a novel Catalytic Reaction of rubidium ion with atomic hydrogen and the hydride ion product
International Journal of Hydrogen Energy, 2002Co-Authors: R L Mills, P RayAbstract:Abstract From a solution of a Schrodinger-type wave equation with a nonradiative boundary condition based on Maxwell's equations, Mills predicts that atomic hydrogen may undergo a Catalytic Reaction with certain atomized elements and ions which singly or multiply ionize at integer multiples of the potential energy of atomic hydrogen, 27.2 eV . The Reaction involves a nonradiative energy transfer to form a hydrogen atom that is lower in energy than unreacted atomic hydrogen with the release of energy. One such atomic Catalytic system involves Rb+ from RbNO3. Since the second ionization energy of rubidium is 27.28 eV , the Reaction Rb+ to Rb2+ has a net enthalpy of Reaction of 27.28 eV . Intense extreme ultraviolet emission was observed from incandescently heated atomic hydrogen and the atomized Rb+ catalyst that generated an anomalous plasma at low temperatures (e.g. ≈10 3 K ) and an extraordinary low field strength of about 1– 2 V / cm . No emission was observed with RbNO3 or hydrogen alone or when noncatalysts, Mg(NO3)2 or Al(NO3)3, replaced RbNO3 with hydrogen. Emission was observed from Rb2+ that confirmed the resonant nonradiative energy transfer of 27.2 eV from atomic hydrogen to atomic Rb+. The catalysis product, a lower-energy hydrogen atom, was predicted to be a highly reactive intermediate which further reacts to form a novel hydride ion. The predicted hydride ion of hydrogen catalysis by Rb+ is the hydride ion H−(1/2). This ion was observed spectroscopically at 407 nm corresponding to its predicted binding energy of 3.05 eV .