Hierarchically porous Pd/SiO2 catalyst by combination of miniemulsion polymerisation and sol-gel method for the direct synthesis of H2O2

The production of hydrogen peroxide H2O2, as an important commodity chemical, attires the attention towards greener processes such as the direct synthesis from hydrogen H2 and oxygen O2, the selectivity being the biggest challenge. Since this reaction is structure-sensitive, the design of appropriate catalysts is required. We propose a novel method to prepare hierarchically porous Pd/SiO2 catalyst by combination of miniemulsion polymerisation to prepare a Pd-containing latex template and sol-gel synthesis in controlled conditions to tailor the silica porosity. The final material displayed a surface area of 711m2 g-1 and a total pore volume of 0.93cm3 g-1. The catalyst was evaluated with different pre-treatments in the direct synthesis of H2O2, where it exhibited structural resistance at the reaction conditions and a stable selectivity of 46±1% towards H2O2.