Enhancing Pd Catalytic Activity by Amine Group Modification for Efficient Direct Synthesis of H₂O₂

A great deal of research has been carried out on the design of Pd-based catalysts in the direct synthesis of H₂O₂, mainly for the purpose of improving the H₂O₂ selectivity by weakening the activation energy on the Pd active site and thus inhibiting the dissociation of the O-O bonds in O₂*, OOH*, and HOOH*. However, this often results in insufficient activation energy for the reaction between H₂ and O₂ on Pd, leading to difficulties in improving both the selectivity and productivity of H₂O₂ simultaneously. Based on this, this study reports an efficient catalyst composed of amine-functionalized SBA-15-supported Pd. The strong metal-support interaction not only makes the PdNPs highly dispersed with more Pd active sites but also improves the stability of the catalyst. The amine group modification increases the proportion of Pd⁰, further enhancing Pd activity and promoting the adsorption and conversion of H₂ and O₂ on Pd, thereby significantly increasing H₂O₂ productivity. Additionally, the density-functional theory simulation results showed that due to the hydrogen-bonding force between the amine group and H₂O₂, this particular anchoring effect would make the hydrogenation and decomposition of H₂O₂ effectively suppressed. Ultimately, both the selectivity and productivity of H₂O₂ are improved simultaneously.