Room temperature selective oxidation of aniline to azoxybenzene over a silver supported tungsten oxide nanostructured catalyst

Abstract

Heterogeneous catalysts comprising silver nanoparticles supported on nanostructured tungsten oxide were applied for room temperature oxidative coupling of aniline to azoxybenzene, an important chemical intermediate and a chemical of industrial interest.

Plasmonic Nanorattles as Next‐Generation Catalysts for Surface Plasmon Resonance‐Mediated Oxidations Promoted by Activated Oxygen

“…As the visible-light excitation comprises the entire visible region, it can excite the SPR of nanorattles,nanoshells, and nanoparticles (whose SPR maxima are centered at different laser wavelengths). [31][32][33][34] Figure 4B shows the conversion (%) for the oxidation of aniline as af unction of time by employing the Au@AgAu nanorattles (black trace), AgAun anoshells (blue trace), and Au nanoparticles (red trace) as catalyst. [31] Although the use of inorganic oxides and metal nanoparticles as catalysts to produce azobenzene in good yields has been reported, the utilization of harsh conditions (strong oxidizing agents,h igh pressures of O 2 and/or temperatures up to 150 8 8C) are still required.…”

Chloride promoted room temperature preparation of silver nanoparticles on two dimensional tungsten oxide nanoarchitectures for the catalytic oxidation of tertiary N-compounds to N-oxides

“…23 The W 4f 5/2 and 4f 7/2 spectra attributed to the binding energies 37.9 eV and 35.8 eV respectively suggesting that the tungsten in the tungsten oxide sample exists as W +6 . 23 (Fig. 2c) The O1s spectrum exhibited peak at binding energy 530.6 eV, which can be attributed to the oxygen bounded to W +6 i.e.…”

“…[23][24][25] Aqueous solution of silver nitrate (0.6 g) was added to vigorous stirred 9.3 g tungstic acid dissolved in deionized water. An aqueous solution of CTAB (1.5 g) was added drop wise to the reaction mixture.…”

“…Insofar, AgW is concerned; our previous reports deal with the synthesis of spherical nanoparticles, 1D nanorods, 3D hierarchical superstructures by one pot synthesis method. [23][24][25] But synthesis of 2D Ag/WO 3 nanoplates and their catalytic applications have not been explored. Oxidation reactions are the most fundamental reaction in organic chemistry.…”

“…48 Similarly, methyltrioxorhenium, 49 manganese porphyrin, 50 Herein, in the present work, we report for the first time room temperature facile synthesis of highly dispersed very small AgNPs (2-5 nm) on 2D WO 3 nanoplates for the oxidation of tertiary Ncompounds to their corresponding N-oxides with hydrogen peroxide as oxidant with very high yield. Our previously reported silver tungsten nanoparticle catalyst selectively converted aromatic primary amine, such as aniline to azoxybenzene with high yield, 23 but the AgW nanoparticles exhibit poor catalytic performance for N-oxidation reaction as compared to that of the AgW 2D nanoplate morphology. It is also well known fact that we know that the catalytic efficiency of nanostructures is primarily governed by the size and shape of the nanocrystals.…”