An experimental and kinetic study of the direct synthesis of hydrogen peroxide from hydrogen and oxygen over palladium catalysts

The catalyzed direct synthesis of hydrogen peroxide (H2O2) from hydrogen and oxygen has the potential to become a lower cost and more environmentally friendly alternative to the commercially practiced anthraquinone process. However, to date safety, selectivity, and product stability challenges have prevented the commercialization of this process. The development of a commercial process will benefit from a detailed understanding of mechanism and kinetics of this challenging reaction. In this study, kinetic modeling and experiments of direct synthesis of hydrogen peroxide were carried out on Pd/Al2O3, PdAu/Al2O3, and halide modified Pd/Al2O3(X) (X = F, Cl, Br) catalysts at atmospheric pressure and at 275 K; the hydrogen and oxygen concentrations in the gas phase were measured and quantified by online mass spectrometry. Kinetic expressions for all relevant elementary reactions were proposed. The kinetic coefficients were optimized by simulating the hydrogen and oxygen consumption rates with time on stream, a...