CO oxidation studies over cluster-derived Au/TiO2 and AUROlite™ Au/TiO2 catalysts using DRIFTS

Spectroscopic Investigation of Titania‐Supported Gold Nanoparticles Prepared by a Modified Deposition/Precipitation Method for the Oxidation of CO

“…In particular, the peak at 2072 cm −1 can be attributed to a linear adsorption of CO on partially negative gold sites and peaks at lower frequencies (2054, 2043, 2013 cm −1 for the sample with the highest metal loading) to multisite adsorption of CO in different bridged configurations, depending on the degree of back‐donation of Au to CO . The absence of carbonyl bands relative to oxidized gold Au n + implies that Au was entirely reduced to zerovalent species as expected by using excess of NaBH 4 and is in agreement with the XPS data. The nature of the negative charge on gold is closely related to the support, in particular regarding the charge transfer between gold particles and M 3+ cations of the support lattice …”

Unravelling the Role of Oxygen Vacancies in the Mechanism of the Reverse Water–Gas Shift Reaction by Operando DRIFTS and Ultraviolet–Visible Spectroscopy

“…The band with minor intensity observed at 1620 cm -1 is typical of carboxylate species 33 . The bands 15 at 1556 and 1360 cm -1 gradually emerged and they can be attributed to formate species on the TiO2 surface 32,34 . These emergence of the two bands were accompanied by those of two weak bands at 2950 and 2870 cm -1 (not shown) that were assigned to νCH of formate species 35 .…”

“…Several spectral features in the range of 1300-1650 cm -1 assigned to carbonates, carboxylates and formate species adsorbed on TiO2 support were observed. The band at 1527 cm -1 is characteristic of the C=O stretch vibration of bidentate carbonates whereas the feature appearing at 1430 cm -1 is commonly assigned to asymmetric stretching vibration νas (COO) of monodentate carbonates 32 .…”

Highly Selective Catalytic Reduction of Nitro- to Azoarenes under Ambient Conditions

“…Selective transformation of nitrobenzene 1a to azobenzene 3a ( Table 1, entries 2-7) was achieved using both the commercially available Au 0 -NPs (d av . * 3 nm) heterogeneous catalysts (Au/TiO 2 , Au/Al 2 O 3 , Au/ZnO) [22][23][24] and home-made Au 0 -NPs supported on Mg-Al hydrotalcite (Au/HT). It is worth to note that without catalyst and/or base only a negligible conversion of 1a was detected ( Table 1, entry 1).…”