Nest-shaped hollow-encapsulated Pd catalyst enhances the catalytic performance of hydrogen peroxide directly synthesizing from hydrogen and oxygen

A well-defined structural morphology can significantly construct a special catalytic micro-reaction environment to enhance the catalytic performance of Pd catalyst in the direct synthesis of hydrogen peroxide from hydrogen and oxygen (DSHP). In this study, SiO 2 was used as a rigid template, PdCl 2 as the Pd precursor, and dopamine hydrochloride (DA) as the carbon and nitrogen source to synthesize a nest-shaped hollow-encapsulated Pd catalyst named Pd Multi @ONHCS. This catalyst was successfully constructed via high-temperature pyrolysis of poly dimethyl diallyl ammonium chloride (PDDA), which generated a blasting effect crucial for this formation. Characterization analysis, catalytic performance evaluation experiment, and molecular dynamics simulation were conducted to explore the structure-performance relationship of Pd Multi @ONHCS catalyst in DSHP. Both experimental and simulation results consistently showed that the nest-shaped hollow structure of Pd Multi @ONHCS catalyst created a distinctive catalytic microreactor environment with a spatial mass transfer constraint, which was not only conducive to adsorption and enrichment of H 2 and O 2 at Pd active sites to produce H 2 O 2 . In addition, the generated H 2 O 2 can be desorbed from Pd active sites in time and rapidly diffused into the reaction solution, effectively inhibiting the dissociation of species containing O O bonds on the Pd surface, resulting in severe hydrogenation and decomposition side reactions, and improving H 2 O 2 productivity and selectivity.