Researchers at the Hefei Institutes of Physical Science, part of the Chinese Academy of Sciences, have achieved a breakthrough in catalyst synthesis, published in Angewandte Chemie International Edition. Their work focuses on creating an efficient electrocatalyst for hydrogen peroxide (H2O2) production and biomass upgrading, with potential applications in various fields such as environment, energy, and healthcare.
Traditionally, H2O2 is produced through energy-intensive processes, but the team explored electrocatalytic synthesis as a more environmentally friendly and efficient alternative, utilizing water and oxygen. This approach requires advanced electrocatalysts for high-yield and selective H2O2 production, and the researchers paid special attention to utilizing the generated H2O2, especially in electrochemical organic oxidation processes, opening avenues for value-added applications.
For their study, the team used bacterial cellulose as an adsorption regulator and carbon source in conjunction with a multi-step approach involving wet chemical impregnation, pyrolysis, and acid etching processes. This resulted in a catalyst called FeSAs/ACs-bacterial cellulose-derived carbon (BCC), composed of oxygen-coordinated Fe single atoms (SAs) and atom clusters (ACs).
Advanced imaging techniques, including aberration-corrected scanning transmission electron microscopy, confirmed the presence of both Fe SAs and clusters. The atomic structure of Fe was determined using X-ray fine structure absorption spectroscopy and X-ray photoelectron spectroscopy.
The catalyst demonstrated excellent electrocatalytic performance and selectivity for the 2-electron oxygen reduction reaction (2e– ORR) under alkaline conditions. Additional experiments confirmed the accumulation of H2O2 in the electrolyte.
The researchers integrated the in situ generated H2O2 with the electro-Fenton process, resulting in a high rate of ethylene glycol conversion and high selectivity for formic acid. This showcased the potential of the electro-Fenton process to enhance biomass-derived feedstocks through oxidative upgrading.
To further improve H2O2 yield, the team developed a three-phase flow cell based on the gas diffusion electrode. Density functional theory analyses revealed that Fe clusters were the actual catalytically active sites in the 2e– ORR process, and the electronic interaction between Fe single atoms and clusters significantly enhanced electrocatalytic performance.
Source: Chinese Academy of Sciences