Ultrafine AuPd Nanoclusters on Layered Double Hydroxides by Capt-Capped AuPd Clusters Precursor Method: Synergistic Effect for Highly Efficient Aerobic Oxidation of Alcohols

A series of Ni3Al–LDH-supported AuPd nanocluster (NC) catalysts AuxPdy/LDH (x/y = Au/Pd ratio upon the molar percentages of Au and Pd to the total metal; LDH: layered double hydroxide) were prepared by modified electrostatic adsorption of captopril-protected AuxPdy NCs onto the predispersed LDH support followed by proper calcination. The systematic characterizations reveal that the ultrafine AuxPdy NCs ranging from 1.4 ± 0.5 to 1.6 ± 0.5 nm with the Au/Pd ratios reducing from 96/4 to 61/39 are mainly dispersed on the edge of small LDH nanosheets in obtained catalysts AuxPdy/LDH. All of the catalysts AuxPdy/LDH exhibit higher aerobic oxidation activity of 1-phenylethanol than the monometallic Au25/LDH, of which the Au87Pd13/LDH (1.5 ± 0.5 nm) shows the highest activity with turnover frequency (TOF) of 6810 h–1 in toluene and an extremely high performance with TOF of 131 400 h–1 under solvent-free condition, attributed to the ultrasmall Au87Pd13 NCs, the most electron-rich Au species formed by the electron ...