Recent Advances in the Direct Synthesis of H₂O₂

Hydrogen peroxide (H 2 O 2 ) is a highly effective, green oxidant that has found application in sectors ranging from the synthesis of fine chemicals and waste stream treatment to the extraction of precious metals and the bleaching of paper pulp and textiles. The growing demand for H 2 O 2 has seen it become one of the 100 most important chemicals in the world. The direct synthesis of H 2 O 2 from H 2 and O 2 has been a challenge for the scientific community for over 100 years and represents an attractive alternative to the current means of production. Herein we discuss the historical perspective of the direct synthesis process, the recent literature regarding catalyst design and the role of additives as well as the application of H 2 O 2 as an in situ oxidant. We discuss the key problems that remain and conclude that although there has been progress with respect to the selectivity of hydrogen utilisation, there is a need to now concentrate on catalyst activity as the key remaining problem requiring a solution is the concentration of H 2 O 2 that can be achieved, especially in flow reactors.