Pd/D CO-DEPOSITION: EXCESS POWER GENERATION AND ITS ORIGIN

摘要

Almost two decades ago, Fleischmann and Pons announced that excess power could be generated by the electrochemical compression of deuterium into a palladium lattice and that its origin is nuclear. Often, the production rates were such that a sudden electrolyte boiling could be observed in cells operating under steady state for a prolonged period of time. In these cells, the generation rate was consistent with that expected for nuclear processes taking place in a fast-breading reactor. Practical difficulties associated with the F-P protocol were three-fold: (i) electrochemical charging occurs via diffusion - an inherently slow process, (ii) there is an undetermined time period separating the time at which a complete saturation with deuterium is achieved and, excess power generation - the so-called incubation time and (iii) poor reproducibility. All these difficulties are related to the metallurgy of palladium electrodes and can be eliminated by employing cathodes prepared by the co-deposition process. Co-deposition is a process whereby palladium is electroplated from a Pd~(2+)-salt solution onto a substrate that does not absorb deuterium (such as Au, Cu, etc.). The applied current and/or potential is adjusted to deposit palladium in the presence of evolving deuterium. SEM analysis of electrodes prepared by Pd/D co-deposition exhibits highly expanded surfaces consisting of small spherical nodules. Cyclic voltammetry and galvanostatic pulsing experiments indicate that, by using the co-deposition technique, a high degree of deuterium loading (with an atomic ratio D/Pd>1) is obtained within seconds. These experiments also indicate the existence of a D~(2+) species within the Pd lattice. Because an ever expanding electrode surface is created, non-steady state conditions are assured, the cell geometry is simplified because there is no longer a need for an uniform current distribution on the cathode, and long charging times are eliminated.