Unveiling the traits of rare earth metal (RM)-substituted bimetallic Ce_0.5RM_0.5V₁O₄ phases to activate selective NH₃ oxidation and NO_X reduction

V₂O₅ contains V⁵⁺ accessible to NO_X/NH₃, thus having partial success in producing N₂ via selective NO_X reduction (SCR) and NH₃ oxidation (SCO). V₂O₅, however, can be advanced by structural modification with rare-earth metal (RM) to form vanadate (RM₁V₁O₄), wherein Lewis acidity of open V⁵⁺ is regulated by the type of RM along with the change in Brönsted acidity/redox character. Herein, TiO₂-supported Ce₁V₁O₄ served as adaptable platform, where half of Ce was replaced by RM (Tb, Er, or Yb) to form Ce_0.5RM_0.5V₁O₄ catalysts. The promotive effect anticipated by RM substitution for Ce_0.5RM_0.5V₁O₄ was insignificant at low temperatures. Conversely, high temperatures tuned the property of Ce_0.5RM_0.5V₁O₄ desirably. Ce_0.5Er_0.5V₁O₄ possessed the greatest Lewis acidity/redox feature, thus revealing the best performance in SCR/SCO at elevated temperatures. Hydro-thermal aging (HT) of the catalysts was repercussive to their properties to some extents and altered the kind of major surface sites for SCR/SCO. Brönsted acidity/redox trait primarily directed low-temperature SCR performance of Ce_0.5RM_0.5V₁O₄ (HT), yet, were the greatest in Ce_0.5Er_0.5V₁O₄ (HT). Meanwhile, Lewis acidity of Ce_0.5RM_0.5V₁O₄ (HT) dominated high-temperature SCR/SCO performance and again was the most desired in Ce_0.5Er_0.5V₁O₄ (HT). This paper demonstrated the vitality of RM innate to Ce_0.5RM_0.5V₁O₄ for accelerating SCR/SCO exposed to periodic HT.