l-Arginine-Functionalized Pd–Ni Catalyst Enhances Direct H2O2 Synthesis in Microreactors

Using an l-arginine (LA)-functionalized Pd–Ni catalyst, hydrogen peroxide (H₂O₂) was directly synthesized via a self-designed microreactor at ambient temperature and pressure. The yield of H₂O₂ achieved 574.31g kg_cat^–1 h^–1, with the concentration of H₂O₂ in the solution reaching 4.05 wt % per hour. After five cycles and online activation, the LA functionalized Pd–Ni catalyst maintained high H₂O₂ catalytic activity. The catalytic activity evaluation experiments, characterization results, and simulation studies demonstrated that Ni doping and LA-functionalization synergistically modulate the electronic structure of the active Pd component. This modulation increases the concentration of Pd²⁺ at the active sites, effectively inhibits the dissociation of the O–O bond in O₂*, OOH*, and HOOH* species, thereby enhancing the catalytic performance for H₂O₂ production. This study proposes a systematic strategy for the design of Pd-based catalysts to directly synthesize highly efficient H₂O₂.