Hydrogen Peroxide Synthesis: An Outlook beyond the Anthraquinone Process

Abstract

Hydrogen peroxide (H₂O₂) is widely used in almost all industrial areas, particularly in the chemical industry and environmental protection. The only degradation product of its use is water, and thus it has played a large role in environmentally friendly methods in the chemical industry. Hydrogen peroxide is produced on an industrial scale by the anthraquinone oxidation (AO) process. However, this process can hardly be considered a green method. It involves the sequential hydrogenation and oxidation of an alkylanthraquinone precursor dissolved in a mixture of organic solvents followed by liquid–liquid extraction to recover H₂O₂. The AO process is a multistep method that requires significant energy input and generates waste, which has a negative effect on its sustainability and production costs. The transport, storage, and handling of bulk H₂O₂ involve hazards and escalating expenses. Thus, novel, cleaner methods for the production of H₂O₂ are being explored. The direct synthesis of H₂O₂ from O₂ and H₂ using a variety of catalysts, and the factors influencing the formation and decomposition of H₂O₂ are examined in detail in this Review.