Electrodes

摘要

A process for simultaneously wet-proofing and catalyzing a carbon-containing electrode comprises contacting the electrode with an organic solvent solution containing a wet-proofing agent for the electrode and a compound represented by the formula wherein M is platinum, palladium, rhodium or iridium; the R groups are the same or different throughout the molecule and are hydrocarbon groups, and n is integer equal to the electrovalence of M, and/or a compound represented by the formula (B) GM1G1, where M1 is platinum, palladium, rhodium, iridium, ruthenium or osmium, and G and G1 are hydrocarbon groups which are pi-bonded to the metal M1, and heating said electrode to the temperature sufficiently high to decompose the noble metal compounds contacted therewith to the elemental metal. R, which may be the same or different salt molecule, may be alkyl, aryl, alkaryl, aralkyl, alkenyl, alkynyl, cycloalkyl and cycloalkenyl and such groups are methyl, ethyl, n-butyl, tert-butyl, 2,2-dimethyl-n-propyl, iso-octyl, decyl, phenyl, phenylethyl, cumyl, mesityl, cyclopentyl, ethylcyclohexenyl, allyl or butyne-2-yl groups. Preferably R contains 1/10 carbon atoms. Solvents may be hydrocarbon, halogenated hydrocarbon, alcohols, ketones and ethers. Numerous examples are specified. The electrode may be of substantially pure carbon such as graphite or activated porous carbon, or of a mixture of carbon with a metal such as nickel or iron, a mixture of carbon with a plastics such as polyethylene or polytetrafluoroethylene or a mixture of carbon with both a metal and a plastics, and carbon with a metal backing. Suitable wet proofing agents are paraffin oils, paraffin waxes, halogenated paraffin oils, halogenated paraffin waxes, polythene, polypropylene, aliphatic monohydroxy alcohols containing between 8 and 18 carbon atoms and glycols of molecular weight between 2000 and 4000 such as polypropylene glycol and polybutylene glycol and halogenated naphthalenes and perfluorochloroethylenes. The compound of Formula A may be in concentration to provide between 0.2 and 5.0 milligrams of metal M per square centimeter of electrode surface and the wet proofing agent may be in amount of between 1 and 3 weight per cent based on the weight of the solvent. The contacting may be by spraying or brushing the solution on to the electrode surface or by immersing the electrode in the solution for 5-10 minutes or longer.ALSO:Organometallic compounds used to pretreat carbon-containing electrodes have general formula GM1G1, where M1 is platinum, palladium, rhodium, iridium, ruthenium or osmium, and G and G1 are hydrocarbon groups pi-bonded to the metal. Specified are, cyclopentadienyl-rhodium-cyclopentadiene, methylcyclopentadienyl-rhodium - methylcyclopentadiene, cyclopentadienyl - iridium - cyclopentadiene, cyclopentadienyl - palladium - cyclopentenyl, dicyclopentadienyl - ruthenium, dicyclopentadienylosmium and cyclopentadienyl-rhodium-cyclo-octa-1,5-diene.