Properties of Palladium-Phosphorus Catalysts Supported on HZSM-5 Zeolite in Direct Synthesis of Hydrogen Peroxide

The properties of Pd/HZSM-5 and Pd–nP/HZSM-5 catalysts were studied in direct synthesis and side processes of decomposition and hydrogenation of H2O2 under mild conditions in ethanol and aqueous ethanol in the presence of an acid inhibitor. It was shown, using HRTEM, XRD, and ICP MS methods, that modification with phosphorus led to the formation of highly dispersed X-ray amorphous systems, which are structurally disordered solid solutions of phosphorus in palladium. The main factors governing the promoting effect of phosphorus on the yield of H2O2 are considered. It was established that the use of a zeolite support in the H form, along with the phosphorus and acid modifiers, inhibits the side process of H2O2 decomposition.