CH 102 1st edition Lecture 25 Outline of Current Lecture I. Hydrogen Can Be Used in Fuel Cells II. Critical Components of the Fuel CellIII. Issues with the Commercial Application of Fuel CellsIV. A Grand Challenge – Reliable and Inexpensive Sources of EnergyV. A Major Issue – Sources of Hydrogen?VI. An Alternative - Direct Methanol Fuel CellsCurrent LectureI. Hydrogen Can Be Used in Fuel Cells a. A fuel cell uses a spontaneous chemical reaction to generate electrical powerb. A fuel cell has two electrodes and an electrochemical reaction occurs at each electrodec. Anode reaction – oxidation occursi. H2 (g) → 2 H+ + 2 e-d. Cathode reaction – reduction occursi. O2 (g) + 4 e- + 4 H+ → 2 H2O (l)e. Net chemical reactioni. 2 H2 (g) + O2 (g) → H2O (l)II. Critical Components of the Fuel Cella. Polymer Membrane electrolytei. Conducts protons across the cellii. Prevents leakage of hydrogen and oxygen b. Electrode Catalystsi. Platinum catalysts increase the rate of hydrogen oxidation and oxygen reductionc. Carbon Supporti. Holds the catalyst particlesii. Make electrical contactIII. Issues with the Commercial Application of Fuel Cellsa. The Platinum Catalystsi. Pt is the best catalystii. There is not enough Pt in the world at any price to supply the demandiii. We must discover a more active catalysts than Pt, that is not Ptb. The Carbon Support These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. With extended use the carbon support is oxidized, eroding away and electrical connection is lostii. We need a more stable carbon supportIV. A Grand Challenge – Reliable and Inexpensive Sources of Energya. The current generation is exhausting the supply of fossil fuelsb. Your generation must find means of providing society with low cost, renewable energy sourcesi. Perhaps returning to nuclear power (Is Jane Fonda still with us?)ii. Biomassiii. Wind Poweriv. Solar EnergyV. A Major Issue – Sources of Hydrogen?a. Sources of Hydrogeni. Electrolysis of water1. Where does the electrical power come from?a. Coal-fired power plants?b. Nuclear energyii. Steam Reforming of Methane1. CH4 + H2O → 3 H2 + COiii. Coal Gasification to Form Syngas1. C + H2O → H2 + COVI. An Alternative - Direct Methanol Fuel
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