High Hydrogen Loading into Thin Palladium wires Through Precipitate of Alkaline_Earth Carbonate on the Surface of Cathode: Evidence of New Phases in the Pd-H System and Unexpected Problems due to Bacteria Contamination in the Heavy Water

A new procedure has been developed at INFN Frascati Laboratory in order to achieve a very high Hydrogen or Deuterium electrolytic loading into a long and thin Palladium wire. This technique consists in the addition of a very small amount of alkaline-earth elements into a very diluted acidic solution.Because of enhancing pH values around the cathode, during the electrolysis, carbonates are able to precipitate onto the cathode's surface forming a thin layer which strongly increases the Pd loading; a computer simulation has been developed to find out the proper working conditions for the carbonates precipitation.Loading results of Hydrogen were excellent (H/Pd= 1). The evidence of a new phase in the Pd-H system was inferred from the basis of the variation of the thermal resistivity coefficient of the Pd wire as a function of the H/Pd ratio.Less satisfactory results were obtained for Deuterium (D/Pd@ 0.85, no excess heat) because of inorganic and organic contamination normally present in ordinary heavy water. A peculiar procedure to purify heavy water, developed at INFN-LNF, has permitted to achieve interesting loading, up to D[Pd=- 0.97, for several days and evidence of overheating of Pd wire i.e. 'excess heat'.We have discovered that the obtained poor results with the heavy water are mainly due to the presence of two kinds of new bacteria living in the commercial reactor-grade heavy water we have used for the loading tests. We named such bacteria (Ralstonia and Stenotrophomonas genera) 'Detusculanense' specie.