Heusler Alloys: A Group of Novel Catalysts.

In this study, we investigated the catalytic properties of various Heusler alloys for the hydrogenation of propyne and the oxidation of carbon monoxide. For propyne hydrogenation, CoFeGe alloy showed a higher activity than that of elemental Co, where neither Fe nor Ge showed any activity. This clearly indicates an alloying effect. For the oxidation of carbon monoxide, although most alloys showed a significant change in catalytic activity during measurement due to an irreversible oxidation of the alloy, CoTiSn alloy showed a very small change. The results indicate that the catalytic activity and stability of a Heusler alloy can be tuned by employing an appropriate set of elements.