Mechanism in chlorine‐enhanced Pd catalyst for H₂O₂in situ synthesis in electro‐Fenton system

Abstract

Palladium-based catalysts have been widely employed in the electro-Fenton process for in situ generation of H 2 O 2 . However, the process is still far from being practical on a large scale. In this work, a series of Cl x FePd/γ-Al 2 O 3 /Al catalysts were prepared by a three-step-impregnation method. They exhibited excellent activity in H 2 O 2 in situ synthesis and high efficiency in phenol degradation. The characterization results showed that Cl could assist in increasing the content of Pd 0 and reducing the isoelectric point of catalysts, which led to the drastic promotion in the synthesis of H 2 O 2 .Theoretical calculations further demonstrated that Cl doping could facilitate the main reaction in H 2 O 2 synthesis, as well as inhibit side reactions such as dissociation of the O O bond. Furthermore, kinetic models were proposed and fitted. A plausible reaction mechanism as well as degradation pathways were elaborated based on electron spin resonance and gas chromatography-mass spectrometry results. These findings illustrate the value of palladium-based Cl x FePd/γ-Al 2 O 3 /Al catalysts for their application in the electro-Fenton process.

Electron‐deficient covalent organic frameworks anchored on melamine sponges for visible‐light‐driven H2O2 evolution

“…As an environmental-friendly oxidant, hydrogen peroxide (H 2 O 2 ) is widely used in chemical production, sewage treatment, and other industrial productions due to its strong oxidizing properties, safe operation, and single by-product (water). [1][2][3] Currently, the conventional production process of H 2 O 2 is the anthraquinone oxidation method, which does not abide by the green-chemistry principles since it requires high temperature and pressure, and meanwhile produces unmanageable contaminants. Therefore, an energy-saving and pollution-free way is urgently required.…”