Synthesis of Bimetallic Au-Ag/CMK-3 Catalysts and Their Catalytic Activity for the Oxidation of Amino Alcohol

Abstract

CMK-3 supported highly dispersed Au-Ag bimetallic nanoparticles with different Ag/Au ratios were prepared by a sequential impregnation–reduction method without the use of any polymer stabilizer. The physicochemical properties of these catalysts were characterized with XRD, ICP-OES, EDS, TEM, XAFS, XPS, STEM, and H2-TPD. The introduction of Ag influenced the surface Ag/Au ratios, particle size, and electronic and structural properties. The relationship between the desorption amount of H2 and the ideal atomic arrangements with different Ag/Au ratios on the (111) planes revealed that the isolated atomic sites on the surface of alloy nanoparticles significantly improved the ability of hydrogen dissociation and the catalytic activity. As a result, compared with the monometallic Au/CMK-3, the conversion of monoethanolamine catalyzed by 10Ag90Au/CMK-3 could increase by 23% and the apparent activation energy was reduced by 10.9 kJ·mol–1.

Au Nanoparticle Catalysts on NiO-Decorated MgO–Al2O3 Supports for Efficient Oxidative Esterification of Methylacrolein to Methyl Methacrylate

“…However, further increases in the Au loading did not improve performance. This may be due to the reduced metal dispersion of the catalysts with higher loads, and the additional metal cannot fully play the active role …”

“…This may be due to the reduced metal dispersion of the catalysts with higher loads, and the additional metal cannot fully play the active role. 46 3.3. Mechanism Study on Catalyst Activity.…”