Coupling of chemical, electrochemical and ultrasonic energies for controlled generation of hydroxyl radicals

Sonoelectro-Fenton process: A novel hybrid technique for the destruction of organic pollutants in water

“…Two previous studies are misleading because they do not really involve EF process [20,21]. Abdelsalam and Birkin [22] suggested the possible combination of sonoelectrochemistry and Fenton's reagent, but their method did not take advantage of the key step, i.e., the catalytic regeneration of Fe 2+ , so they could not draw the main conclusions that we present here.…”

Intrinsic Iron‐Containing Multiwalled Carbon Nanotubes as Electro‐Fenton Catalyst for the Conversion of Benzene to Redox‐Active Surface‐Confined Quinones

“…To decompose carcinogenic BZ to non‐hazardous compounds like phenols, quinones, maleic anhydride, and CO 2 ,– the following chemical reagents are widely used: high‐valent oxidants such as potassium permanganate, sodium dichromate, cerium species, peroxy disulfate, and hydroxyl ions derived from Fenton system, where the ferrous ion is reacted with H 2 O 2 –. Similar to the Fenton system, electro‐Fenton reagents,, in which either Fe 2+ or H 2 O 2 is continuously electro‐generated in the reaction medium under direct electrochemical– and photoelectrochemical conditions, have been reported. Apart from that, heterogeneous catalytic reaction systems in the presence of a co‐oxidant (O 2 , H 2 O 2 ), such as a copper zeolite, heteropolyacid, and Pd(OAc), immobilized hexagonal mesoporous silica and polyimine, V 2 O 5 , chloro triphosphazenyl‐anchored mesoporous silica, CuCr 2 O 4 , carbon nanotubes, or second‐generation Fenton reagents, in which iron ions or iron‐based compounds immobilized ex situ on the electrode surface, for instance, Fe‐PbO 2 /Ti anodes, Fe 3 O 4 /CMK‐3, and iron electrodes reacted with H 2 O 2 have also been reported in the literature.…”

Preparation of Highly Dispersed Pd–Cu on Silica for the Aerobic Hydroxylation of Benzene to Phenol Under Ambient Conditions

“…The process is known for its very low yields (&5% based on the amount of benzene initially used) and for the large amounts of by-products such as acetone and a-methylstyrene [1]. To overcome these problems several attempts have been made for the synthesis of phenol by the direct oxidation of benzene with various oxidants e.g., O 2 [3][4][5], H 2 O 2 [6][7][8][9][10][11][12], N 2 O [13][14][15][16][17][18][19][20][21], H 2 ? O 2 [22][23][24][25], air/CO [26], and O 2 /H 2 O [27].…”