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 kgcat–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.