High Selective Direct Synthesis of H₂O₂ over Pd₁@γ‐Al₂O₃ Single‐Atom Catalyst

Abstract

Abstract Pd‐based catalysts are essential for direct synthesis of H 2 O 2 from H 2 and O 2 , which still need further improvement of the activity and selectivity by engineering the status of Pd active species. In this work, isolated Pd atoms anchored on Al vacancy of the γ‐Al 2 O 3 (100) surface (Pd 1 @γ‐Al 2 O 3 (100)) are proposed to act as a heterogeneous catalyst for direct synthesis of H 2 O 2 from first‐principles theoretical study and micro‐kinetic analysis. The thermodynamic stability and whole catalytic mechanism for conversion of O 2 to H 2 O 2 on Pd 1 @γ‐Al 2 O 3 (100) was studied. It is found that the high selectivity toward H 2 O 2 of Pd 1 @γ‐Al 2 O 3 (100) is attributed to the high oxidation state of isolated Pd active sites with high stability against atom‐aggregation, derived from the strong electronic metal‐support interaction. The formation of 3+ cation state of isolated Pd atoms activates adsorbed oxygen molecule for hydrogenation and simnutaously restrains the formation of intermediate toward by‐product, compared with traditional bulk Pd catalyst in the metallic state. This work provides theoretical insights into the feasibility of atom‐level dispersion Pd to catalyze direct synthesis of H 2 O 2 and guidance for its future development.