Search

The regulation behavior of oxygen vacancies (Vo) at different spatial positions (surface or bulk) in catalysts for selective O 3 catalyzation, along with the reaction pathways evolution was well-investigated in α-MnO 2−x /O 3 systems. Combined characterization methods, systematic organic removal experiments, structure-activity relationship analysis, and theoretical calculations were employed to unveil O 3 decomposition and electron transfer behaviors regulated by surface or bulk Vo. The contribution of electron transfer process (ETP) to atrazine (ATZ) removal was reinforced from 5.2 % to 34.8 % with the formation of bulk Vo, and Vo-rich α-MnO 2−x -2/O 3 system achieved ∼96.5 % ATZ removal along with improved TOC mineralization (∼38 % vs. ∼20 %). Surface Vo facilitated O 3 adsorption, promoting its decomposition into •OH, while bulk Vo not only accelerated •OH production but also withdrew electrons from organics to build ETP. This study shed light on precise modification of metal-based catalysts with Vo to modulate •OH/ETP synergistic processes in catalytic ozonation for efficient water purification. [Display omitted] • Rational Vo modification in catalysts promoted selective ozone catalyzation. • The reaction pathways (•OH and ETP) were modulated by surface and bulk Vo. • Both surface and bulk Vo boosted electrons transfer to decompose O 3 into •OH. • Bulk Vo preferred to withdraw electrons from the organics to build ETP. • •OH and ETP synergistic process facilitated the stoichiometry efficiency of O 3. [ABSTRACT FROM AUTHOR]

Surface engineering has been identified as an effective way to maximize the utilization of noble atoms and facilitate the oxygen reduction reaction. However, a cost-effective and highly durable platform for tailoring the electrocatalytic activity, is still absent. Herein, we demonstrate a new and promising catalytic material of antiperovskite-typed PdNFe 3 and construct a high performance PdNFe 3 @Pd catalyst with atomic layers of strained Pd shell. The PdNFe 3 @Pd/C catalyst presents a high mass activity (MA) of 1.14 A mg−1 Pd at 0.9 V, which is 9 and 6 times higher than those of the Pt/C and Pd/C, respectively. More importantly, the excellent performance of PdNFe 3 @Pd/C was also verified in anion-exchange membrane fuel cells and rechargeable Zn−air batteries. Density functional theory calculations reveal that the strain effect aroused by the lattice mismatch between PdNFe 3 core and Pd shell contributes to the enhanced ORR performance by optimizing the binding strength of oxygen intermediates on Pd. [Display omitted] • Demonstrating a new class of platform/core materials for constructing core-shell catalysts. • Elucidating catalytic mechanism of PdNFe 3 @Pd towards ORR. • Extraordinary catalytic performance towards oxygen reduction. [ABSTRACT FROM AUTHOR]