Utilizing Amorphous/Crystalline Interfaces in Bismuth Nanoparticles to Boost Hydrogen Peroxide Electrosynthesis

Bismuth‐based catalysts hold significant promise for the electrochemical production of H 2 O 2 via the two‐electron oxygen reduction reaction (2 e − ORR) pathway, offering an environmentally friendly and energy‐efficient alternative to traditional methods. However, the influence of bismuth‐based catalysts with varying crystallinity on the 2 e − ORR performance remains an unresolved challenge. Herein, we investigate the relationship between the crystallinity of metallic bismuth catalysts and their catalytic performance for the 2 e − ORR for the first time. Density functional theory (DFT) calculations reveal that the amorphous‐crystalline interface creates a built‐in electric field, boosting charge density and electron transfer as well as enhancing the adsorption of the key intermediate of *OOH and promoting the 2 e − ORR pathway while suppressing the 4 e − ORR. Electrochemical measurements confirm that amorphous‐crystalline Bi (a/c‐Bi) nanoparticles exhibit the best 2 e − ORR performance with an exceptionally high selectivity of 98.54%. Further tests on H 2 O 2 production show that the maximum current density reaches 90 mA cm −2 , significantly boosting the H 2 O 2 yield to 5.52 mol g cat −1 h −1 . Meanwhile, the Faradaic efficiency (FE) remains high at 90.2%. This study provides valuable insights into the design of highly active two‐electron oxygen reduction catalysts by effectively modulating the electron density of bismuth‐based catalysts through crystal engineering.