Vanadium in strongly correlated electron system Ni1-xVxWO4: Paradoxically boosted deNOx reaction under SOx environment via modulating electron correlation

Abstract

The persistent challenge of NOx selective catalytic reduction degradation in the presence of SOx has remained unresolved for decades. In this study, we report a paradoxical boosted denitration performance more than 20% under the SOx environment through controlling the charge state of V utilizing strongly correlated electron systems (SCES) in Ni1−xVxWO4. Substitutional doped V at the Ni site, and the computed charge gap from DFT confirms the SCES. Through the manipulation of the strong correlation between V and Ni, V preserves the between + 2–3 charge state in the presence of SOx. Furthermore, we achieved a stable oxidation/reduction cycle and higher denitration efficiency by altering the oxidation point of (NH4)HSO4-contaminated Ni1−xVxWO4. This results from deliberate decrease in Coulombic repulsion between Ni and V, improving electron transfer for catalytic performance. This revelation offers a resolution of exceptional denitration performance within SOx in industrial exhaust systems, exploiting the foundational principles of SCES. © 2023 Elsevier B.V.