Oxidation of alkenes to 1,2-diols: FT-IR and UV studies of silica-supported sulfonic acid catalysts and their interaction with H2O and H2O2

Insight into the Discriminative Efficiencies and Mechanisms of Peroxy Activation via Fe/Cu Bimetallic Catalysts for Wastewater Purification

Fe/Cu bimetallic catalysts have a synergistic effect that can effectively enhance catalytic activity, so Fe/Cu bimetallic catalysts have been extensively studied. However, the efficacy and mechanisms of Fe/Cu bimetallic catalysts' peroxidation activation have rarely been explored. In this study, Fe/Cu bimetallic materials were fabricated to catalyze different oxidizing agents, including peroxymonosulfate (PMS), peroxydisulfate (PDS), peroxyacetic acid (PAA), and hydrogen peroxide (H2O2), for the degradation of sulfamethoxazole (SMX). The Fe/Cu/oxidant systems exhibited an excellent degradation efficiency of sulfamethoxazole (SMX). In the Fe/Cu/PMS, Fe/Cu/PDS, and Fe/Cu/PAA systems, the main reactive oxygen species (ROS) responsible for SMX degradation were hydroxyl radical (•OH) and singlet oxygen (1O2), while the main ROS was only •OH in the H2O2 system. The differences in the surface structure of the materials before and after oxidation were examined, revealing the presence of a large amount of flocculent material on the surface of the oxidized PMS material. Anion experiments and actual body experiments also revealed that the PMS system had a strong anti-interference ability. Finally, a comprehensive comparison concluded that the PMS system was the optimal system among the four oxidation systems. Overall, this work revealed that the PMS oxidant has a better catalytic degradation of SMX compared to other oxidizers for Fe/Cu, that PMS generates more ROS, and that the PMS system has a stronger resistance to interference.

Organocatalytic activation of hydrogen peroxide: towards green and sustainable oxidations

The advent of organocatalysis provided an additional option in every researcher's arsenal, towards the development of elegant and sustainable protocols for various organic transformations. Oxidation reactions are considered to be key in organic synthesis since oxygenated functionalities appear in many natural products. Hydrogen peroxide is categorized as a green oxidant, since its only by-product is water, offering novel opportunities for the development of green and sustainable protocols. In this review article, we intend to present recent developments in the field of the organocatalytic activation of hydrogen peroxide, providing useful insight into the applied oxidative protocols. At the same time, we will present some interesting mechanistic studies, providing information on the oxygen transfer processes.

Sulfonated polydivinylbenzene bamboo-like nanotube stabilized Pickering emulsion for effective oxidation of olefins to 1,2-diol

Sulfonated polydivinylbenzene bamboo-like nanotube (SPDVB) with effective olefins oxidation activity is prepared by combining cationic polymerization and sulfonation. By merely adjusting sulfonation time, SPDVB with different sulfonic acid group (-SO₃H) contents is achieved. SPDVB is used as both a solid emulsifier and catalyst to fabricate Pickering emulsion interface catalytic system for oxidizing olefins with 30% H₂O₂ acting as oxidant/water phase and olefins acting as reactants/oil phase. It is shown that Pickering emulsion interface catalytic system stabilized by SPDVB exhibits enhanced olefins oxidation efficiency than the conventional ones. At the optimum catalyst and reaction condition, the conversion of olefins by Pickering emulsion interface catalytic system stabilized by SPDVB for cyclohexene, 1-methylcyclohexene, cyclooctene, 2,3-dimethyl-2-butene oxidation is higher than 90.00% and the corresponding 1,2-diol selectivity exceeds 93.00% except the selectivity to 1-methyl-1,2-cyclohexanediol. The catalytic system also exhibits excellent cycling performance (>95.00% olefins conversion and >89.00% 1,2-diol selectivity for cyclohexene/2,3-dimethyl-2-butene oxidation after four cycles). A possible mechanism for oxidation of olefins to 1,2-diol by SPDVB stabilized Pickering emulsion is proposed: the high catalytic interface area between sulfonic acid group and H₂O₂ in water phase enhances the sulfonic acid group of SPDVB to convert into peroxysulfonic acid (catalytic activity centre) firstly; then the formed peroxysulfonic acid attacks the double bond of olefins to form epoxide intermediates, which will be hydrolyzed to 1,2-diol.

A unique opportunity for the utilization of glass wastes as a resource for catalytic applications: toward a cleaner environment

n-glass-waste-SO₃H at the service of catalytic application.