Gold catalysts supported on nanostructured Ce–Al–O mixed oxides prepared by organic sol–gel

Structure‐Activity Relationships of Au/Al2O3 Catalyst for the Selective Oxidative Esterification of 1,3‐Propanediol and Methanol

“…It should be noted that the position of the plasmon peak may depend on two factors: (i) the dielectric function of the medium surrounding the particles, ϵ 0 , and (ii) gold particle size . Also, some of gold hydroxide (or Au 2 O 3 ), water or urea may be present on the surface of Au/Al 2 O 3 in the complex process of Au NPs formation from gold hydroxide particles due to their sequential thermal decomposition: Au(OH) 3 →Au 2 O 3 →Au in the temperature interval 105–250 °C, which can change the values of dielectric constant of the medium surrounding the gold particles (ϵ 0 ) . This results in the plasmon resonance band exhibiting blue shift and bandwidth narrowing with the increase of calcination temperature.…”

Plasmon resonance of gold nanoparticles supported on Y-zeolite in the presence of various co-cations

“…This band is associated with the surface plasmon of Au NPs [63][64][65]. At this temperature NH 3 ligands of the [Au(NH 3 ) 4 ] 3+ complex were gradually released causing the reduction of Au +/3+ cations with final formation of Au NPs [59,62]. So, the first change in the spectrum was associated with the reduction and aggregation of gold species.…”

“…The presence of both Au + and Au 3+ species was confirmed by XPS data for Cu-containing samples, while for Ni-and Fe-containing gold samples only Au 3+ species were observed. The features in the range 280-360 nm correspond to the charge transfer band between gold and oxygen species as described in [58,61,62]. It should be noted that the initial sodium form of zeolite was characterized by adsorption in this wavelength range.…”

Gold nanoparticles supported on magnesium oxide as catalysts for the aerobic oxidation of alcohols under alkali-free conditions

“…1. The spectrum is characterized with the adsorption band at 350 nm (shown with arrow) which can be assigned to gold hydroxide species [43]. It is well established that the presence of metallic gold NPs could be easily detected with the band at ca.…”