| Popis: |
An examination has been made of the heat production at ten palladium electrodes, each prepared in a different way. Seven of these produced heat during D2 evolution in a D2-O2 electrolysis cell (no recombination attempted) which coincided precisely with the prediction of classical electrochemical theory, and thus eliminated the suspicion of heat through unintended D2-O2 recombination. Three electrodes clearly produced an excess heat of ~2-5 watts-cm -3 . The heat was observed for periods of 10-33 hrs. In one electrode the excess heat production "shut off" (after 33 hrs) with no apparent cause: it did not return in five days of further electrolysis. Fleischmann and Pons (1) reported the production of heat during the electrolysis of D2O at a Pd cathode and Pt anode in excess of that predicted by the electrochemical theory for the heat production in cells. Some of the measurements even indicated that the total energy out of the cell as heat was greater than that going in as electricity. The paper attracted attention because it was suggested that the excess heat was due to D-D fusion occurring in Pd at high overpotential. A principal difficulty, since the announcement in March 1989, has been that many electrochemically inexperienced investigators have tried, but failed, to reproduce the alleged heat (however, cf. Huggins (2), Landau (3), McKubre (4), Appleby and Srinivasan (5), Wadsworth (6)). In this note, we report the observation of this excess heat effect in three electrodes out of ten prepared and examined. The calorimeter used in the study was of the heat transfer type. The cell is a glass cylinder 10 cm. high and 5 cm in diameter. The cap is made of 1 cm thick Teflon with holes for the electrodes, the Joule heater and the temperature probe. The cell is placed inside another glass cylinder 12 cm. high and 7 cm. in diameter. For good heat transfer the space between the cylinders is filled with ethylene glycol. The assembly is immersed in a constant temperature bath (0.01°C accuracy) and the temperature difference between the bath and the cell is monitored with thermistor thermometers (Omega 700 series thermistors with 0.01°C resolution). The calorimeter was calibrated by passing different amount of direct current through the electric heater (resistance 275 Ω) in the solution of 0.1 M LiOD (made by dissolution of Li in D2O) and noting the potential drop across it. For each value of the electrical power put in, steady state temperature difference (monitored on a y-t recorder) was noted and plotted to yield a |
