Heterogeneous Catalysis by Tetraethylammonium Tetrachloroferrate of the Photooxidation of Toluene by Visible and Near-UV Light

Abstract

Titanium dioxide is the most extensively used heterogeneous catalyst for the photooxidation of toluene and other hydrocarbons, but it has low utility for the synthesis of benzyl alcohol, of which little is produced, or benzaldehyde, due to further oxidation to benzoic acid and cresol, among other oxidation products, and eventually complete mineralization to CO 2. Et 4 N[FeCl 4 ] functions as a photocatalyst through the dissociation of chlorine atoms, which abstract hydrogen from toluene, and the photooxidation of toluene proceeds only as far as benzyl alcohol and benzaldehyde. Unlike TiO 2 , which requires ultraviolet (UV) irradiation, Et 4 N[FeCl 4 ] catalyzes the photooxidation of toluene with visible light alone. Even under predominantly UV irradiation, the yield of benzyl alcohol plus benzaldehyde is greater with Et 4 N[FeCl 4 ] than with TiO 2. Et 4 N[FeCl 4 ] photocatalysis yields benzyl chloride as a side product, but it can be minimized by restricting irradiation to wavelengths above 360 nm and by the use of long irradiation times. The photonic efficiency of oxidation in one experiment was found to be 0.042 mol/einstein at 365 nm. The use of sunlight as the irradiation source was explored.

Organic–inorganic interactions revealed by Raman spectroscopy during reversible phase transitions in semiconducting [(C2H5)4N]FeCl4

“…[(C 2 H 5 ) 4 N]FeCl 4 which is insoluble in toluene functions as a photocatalyst by dissociating chlorine atoms, which abstracts hydrogen from toluene, and photooxidation only occurs to the extent that benzyl alcohol and benzaldehyde. 20 This low cost compound has a potential to lead the photooxidation of other hydrocarbons and therefore it can be an important material in the synthesis of pharmaceuticals (alcohols).…”

“…A number of complexes with a tetrahedral tetrachloroferrate( iii ) anion [FeCl 4 ] − mixed with organic cation have been reported for their interesting catalytic properties. 15–18 For instance, the tetraethylammonium tetrachloroferrate ([(C 2 H 5 ) 4 N]FeCl 4 ) compound has already been used as photocatalyst for the oxidation of the cyclohexane 19 and the toluene 20 under visible light. This is a notable advantage over TiO 2 compound which requires ultraviolet (UV) irradiation to induce a photocatalytic oxidation of toluene.…”

Photooxidation of Cyclohexane by Visible and Near-UV Light Catalyzed by Tetraethylammonium Tetrachloroferrate

“…In Equation (9), a, b, and c are derived from the rate constants in the mechanism [13], and P represents the combined yield of cyclohexanol and cyclohexanone. The data from Table 3 were fit to this equation, as shown in Figure 3.…”

Heterogeneous reaction of toluene/NO2/O3 on α-Fe2O3 nanoparticles: the impacts of O3, light illumination, and relative humidity on the formation of N-containing organic compounds (NOC)

“…Self-reaction of benzylperoxyl radicals can occur subsequently to form a benzyloxy radical. 54 The NO 2 molecule can react with the radical site of the benzyloxy radical to form benzyl nitrate on the particle surface. 37 Moreover, gaseous NO 2 can also adsorb on the surface of α-Fe 2 O 3 nanoparticles to form adsorbed N 2 O 4 and nitrite.…”