Au‐coverage‐dependent coordination engineering of <scp>PdAu</scp> catalysts for ambient direct synthesis of <scp> H ₂ O ₂

Abstract

Au alloying tunes Pd coordination to enhance selectivity for direct synthesis of H 2 O 2 (DSHP), but the structure–activity relationship remains unclear. We fabricated Pd@Au x core–shell catalysts with controlled Au coverage via H 2 purging and evaluated them in a microreactor under ambient conditions in pure water. H 2 O 2 formation shows a volcano‐shaped trend vs. Pd/Au ratio. The optimal Pd/Au≈1:1 gives 1785 ppm H 2 O 2 and a yield of 190.8 mol·kgcat −1 ·h −1 . DFT calculations reveal a similar volcano‐shaped trend for Au loading. Pd–Au 3 exhibits the lowest free energy for O 2 protonation to OOH (Δ G  = −0.15 eV) and the highest barrier for the four‐electron side reaction (1.31 eV), achieving optimal activity and selectivity. This originates from a moderate d‐band center at −1.80 eV, lying in the Sabatier regime. This work provides insights into Au‐loading regulation on Pd, guiding rational catalyst design.