Passivating the pH-Responsive Sites to Configure a Widely pH-Stable Emulsifier for High-Efficiency Benzyl Alcohol Oxidation

Porous ionic liquids for oxidative desulfurization influenced by electrostatic solvent effect

Developing a highly efficient strategy for the stabilization of the solid-liquid interface is a persistent pursuit for researchers. Herein, porous ionic liquids based on UiO-66 (Zr) porous materials were synthesized and applied to the selective desulfurization catalysis, which integrates the permanent pores of porous solids with the exceptional properties of ionic liquids. Results show that porous ionic liquids possess high activity and selectivity for dibenzothiophene. Experimental analysis and density functional theory calculations revealed that the ionic liquids moiety served as an extractant to enrich dibenzothiophene into the porous ionic liquids phase through the π···π and CH···π interactions. Additionally, the electrostatic solvent effect in the porous ionic liquids contributes to the stabilization solid-liquid interface, which was favorable for UiO-66 moiety to catalytically activate hydrogen peroxide (H2O2) to generate ·OH radicals, and subsequently oxidized dibenzothiophene to the corresponding sulfone. It is hoped that the development of porous ionic liquids could pave a new route to the stabilization of the solid-liquid interface for catalytic oxidation.

Preparation and Emulsifying Properties of Carbon-Based Pickering Emulsifier

Water is increasingly being used as a solvent in place of organic solvent in order to meet the demand for green chemical synthesis. Nevertheless, many of the reaction substrates are organic matter, which have low water solubility, resulting in a low reaction interface and limiting the development of organic-water biphasic systems. A surfactant is typically added to the two-phase system to form an emulsion to increase the contact area between the organic phase and the water. Compared to ordinary emulsion stabilized with the surfactant, Pickering emulsion offers better adhesion resistance, biocompatibility, and environmental friendliness. It possesses unrivaled benefits as an emulsifier and catalyst in a two-phase interfacial catalysis system (PIC). In this study, the amine group (NNDB) was employed to alter the surface of graphene oxide (GO). A stable Pickering emulsion was created by adsorbing GO-NNDB on the toluene–water interface. It was determined that the emulsion system had good stability by analyzing digital photographs and microscope images of droplets at various temperatures, and fluorescence microscopy images of emulsion droplets created by both newly added and recovered emulsifiers. This work provided the groundwork for future applications of Pickering emulsion in interfacial catalysis.