Rare-Earth manganites: surface-segregated platinum increases catalytic activity.
Crushed and etched lanthanum lead manganite (La(0.7)Pb(0.3)MnO(3)) crystals containing as little as 0.005 atomic percent platinum have significantly higher catalytic activity than free platinum crystals. This higher activity is due to an almost 100-fold segregation of platinum on the surface. The surface platinum concentration found, 0.5 atomic percent, is sufficient to account for the enhanced activity provided that the platinum has the same activity as platinum supported on alumina.
Croat
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Tibbetts
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Katz
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