Catalysis Today, Vol.280, 259-265, 2017
Supported bimetallic AuPd clusters using activated Au-25 clusters
Bimetallic AuPd nanoparticles on alumina supports were prepared using Au-25(SR)(18) precursors activated by mild calcination or LiBH4 treatment, followed by selective deposition of Pd via ascorbic acid reduction. Comparison of their catalytic activity for the oxidation of crotyl alcohol showed that bimetallic structure had significantly improved catalysis compared to Pd/Al2O3. In particular, AuPd samples grown from LiBH4-activated Au-25 clusters exhibit the highest catalytic activity as well as high selectivity towards crotonaldehyde formation, likely due to their smaller particle sizes as compared to AuPd samples grown from calcined Au-25 clusters. X-ray absorption spectroscopy (XAS) at the Au L-3-edge, Pd L-3-edge and Pd K-edges showed that the resulting bimetallic AuPd nanoparticles had Au-Pd core-shell structures with a 4d-electron poor Pd surface. (C) 2016 Elsevier B.V. All rights reserved.