Properties of palladium-phosphorus catalysts supported on HZSM-5 zeolite in the direct synthesis of hydrogen peroxide

The properties of Pd/HZSM-5 and Pd–nP/HZSM-5 catalysts in direct synthesis and side processes of decomposition and hydrogenation of H2O2 under mild conditions in ethanol and aqueous-ethanol medium in the presence of an acid inhibitor were studied. Using HR-TEM, XRD and ICP MS methods, it was shown that as a result of modification with phosphorus, X-ray amorphous highly dispersed systems are formed, which represent structurally disordered solid solutions of phosphorus in palladium. The main reasons for the promoting effect of phosphorus on the yield of H2O2 are considered. It has been established that, along with phosphorus and acid modifiers, the use of a zeolite support in the H-form favors the inhibition of the side process of H2O2 decomposition.