Co₂ FeGe Heusler Alloy Nanoparticle Catalysts for Propyne Hydrogenation and Ammonia Decomposition

Heusler alloys (X₂ YZ) can be a candidate for new catalysts as well as other intermetallic compounds. We previously found good catalytic properties of Co₂ FeGe for selective hydrogenation of alkynes and developed nanoparticles of Co₂ FeGe supported on SiO₂ . However, the average diameter of the nanoparticles was 23 nm, which is not small enough compared to those of state-of-the-art nanoparticle catalysts. In this study, we developed SiO₂ -supported Co₂ FeGe nanoparticles of <10 nm in diameter. A catalytic test for selective hydrogenation of propyne indicated a partial formation of sites with low selectivity including excess Co atoms. For ammonia decomposition, enhancement of turnover frequency was achieved by reducing the particle size.