Solid Acid Additives as Recoverable Promoters for the Direct Synthesis of Hydrogen Peroxide

The effectiveness of Cs-exchanged phosphotungstic acid as a recoverable solid acid additive for the direct synthesis of hydrogen peroxide (H₂O₂) using an Au–Pd/TiO₂ catalyst is investigated and compared to the promotion effect of common oxides and nonhalo acids. A clear improvement in catalytic activity toward H₂O₂ synthesis is reported when utilizing Cs-containing heteropolyacids in addition to a standard H₂O₂ synthesizing catalyst. The effect of Cs content on the promotion of H₂O₂ formation is investigated, and the feasibility of a reusable heterogeneous additive has been explored revealing that the presence of the acid additive not only stabilizes the H₂O₂ that is produced but also increases the H₂O₂ synthesis rate