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[Display omitted] • Oxygen vacancies enhance the interaction between the support and Pd-Co NPs. • Co atom strengthens the adsorption of reactants on the Pd atoms. • Pd-Co/TiO 2 -Vo shows excellent small molecule reduction performance. Small molecules are converted into high-value products through electrochemical methods, which are considered as potential substitutes for traditional industrial methods. To reduce the use of precious metal and modulate the local environment by oxygen vacancies, Pd-Co nanoalloys supported on TiO 2 with oxygen vacancies (Vo) are prepared through a facile pyrolysis approach. The superior ORR performance is obtained comparing to the commercial Pt/C (20 wt%) catalysts in alkaline solution. Moreover, the catalyst has amazing catalytic activity for NRR. The synergistic effect of Pd-Co alloys and the Vo greatly improves the yield of NH 3 (4.11 µg/(h·cm2)) and the Faradaic efficiency (2.83%). The performance of small molecular reduction is enhanced by the strong metal-support interactions (SMSI), which agree with the density functional theory (DFT) calculations results. It is anticipated that the established nanoalloy electrocatalysts with modulation of metal–support interactions provide guidance for designing heterogeneous electrocatalysts with high efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • Development of a slab model for alumina-loaded Pt/Ba, considering the effects of both sites simultaneously. • The species exchange process of nitrogen-containing species between proximate Ba and Pt sites is different from the conventional view. • A good linear relationship between NOx adsorption energy and its migration energy barrier. • Detailed electronic structure analysis reveals the reason in essence. Based on density functional theory (DFT) calculations, NO x tends to migrate from Ba to Pt sites within the Lean NO x trap (LNT), rather than reacting at Pt sites before migrating to Ba sites for storage as traditionally believed. Compared with NO and N 2 O, NO 2 has the highest migration energy barrier, and there is a good linear relationship between the adsorption energy of NO x and its migration energy barrier. Furthermore, the essential cause of the above phenomenon is revealed. This study contributes to the exchange of NO x between noble metal catalytic sites and alkaline earth metal storage sites within the LNT. [ABSTRACT FROM AUTHOR]