AN IMPROVEMENT IN THE PROPERTIES OF HYDROGEN STORAGE ALLOY BY COPPER MICROENCAPSULATION

A hydrogen storage alloy of LaNi5 was microencapsulated by electroless chemical plating with metallic copper. The surface morphology of the microencapsulated LaNi5 was studied for different electroless plating conditions. The deactivation, regeneration, and catalytic activity of LaNi5 were compared before and after the microencapsulation. The amount of Cu deposited on the LaNi5 surface increased with increasing concentration of the plating solution. A relatively smooth morphology was obtained by decreasing the plating rate. The extent of the deactivation of the microencapsulated LaNi5 was very low compared to that of LaNi5 and decreases with the number of the microencapsulation. Almost complete regeneration was achieved for microencapsulated LaNi5, but the extent of the regeneration decreased with the number of regeneration cycles at higher temperatures. The microencapsulated LaNi5 showed a higher catalytic activity for methanation of carbon monoxide, where the conversion was almost quantitative.