Tuning the local electronic structure of SrTiO3 catalysts to boost plasma-catalytic interfacial synergy

Abstract

Boosting plasma-catalyst synergy to enhance volatile organic compounds (VOCs) decomposition remains a challenge. Herein, rich oxygen vacancies (V_O) were engineered into the SrTiO₃ catalysts through a facile nitrogen incorporation strategy for the plasma-catalytic decomposition of toluene and ethyl acetate. 100% toluene conversion with 81% CO₂ selectivity at a competitive energy efficiency was achieved under ambient conditions. The characterization results and theoretical calculations evidenced that the partial substitution of oxygen by nitrogen triggered the electronic reconstruction and local disorder, thus modulating the electronic properties and coordination structures contributed to the formation of V_O-Ti³⁺ pairs. Quasi in-situ EPR, operando OES, and operando DRIFTS originally demonstrated that the V_O-Ti³⁺ pairs as active sites promoted the plasma-catalytic synergy instead of isolated V_O. Importantly, the V_O-Ti³⁺ pairs with favorable electron transfer characteristics energetically preferred to capture and utilize vibrationally excited oxygen species. And the lattice oxygen supplied by the V_O-Ti³⁺ pairs were more vigorously activated by the plasma to participate in the surface/interface reaction. This work advances our understanding of the real active sites in plasma-catalytic interfacial synergy and thus paving the way for the rational design of efficiently heterogeneous catalysts.

Keywords: Local electronic structure; Operando characterization; Plasma catalysis; Synergy; VOC.