Carbonate formation structural deposition

Cobalt porphyrins and phthalocyanines were used as precursors for preparation of carbon supported cobalt catalysts that displayed high activity in reduction of oxygen in fuel cells [9-12], These samples were prepared by deposition of cobalt phtalocyanine on active carbon following by heat treatment at 650-700°C in an inert atmosphere providing formation of Co-N structure deposited on active carbon. 

Pyrolitic carbons can be deposited onto finished implants from hydrocarbon gas in a fluidized bed at a controlled temperature and pressure. The anisotropy, density, crystallite size and structure of the deposited carbon can be controlled by temperature, composition of the fluidized gas, the bed geometry, and the residence time (velocity) of the gas molecules in the bed. The microstructure of deposited carbon should be highly controlled, since the formation of growth features associated with uneven crystallization... 

The rate of carbon formation is far less on noble metals than on nickel and this behaviour appears to be related to the difficulty found by noble metals of dissolving carbon in bulk. ° The carbon formed on the surface of noble metals was found to be almost indistinguishable from the catalyst particles. High-resolution TEM images taken from a ruthenium catalyst employed in the SMR reaction revealed a structure in which a few carbon layers were deposited on the surface of the Ru particles. The mechanism by which whiskers grow on the surface of the nickel particles becomes blocked by sulphur poisoning of the catalyst surface. In this specific case, several octopus carbon filaments or whiskers are formed on a given nickel particle. A similar carbon structure has been reported to develop on Ni-Cu alloy catalysts with low nickel contents (20 wt%).ii... 

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