Role of delocalized electrons on the doping effect in vanadia

Summary

Redox chemistry plays an important role in the precise production of targeted valuable chemicals. However, achieving accurate control of the redox process still lacks the guidance of mechanistic insight. This paper describes how doping can enhance redox performance of vanadia for chemical looping oxidative propane dehydrogenation. By elucidating the dynamic redox process of vanadia, we discovered that molybdenum (Mo) dopant lowers the phase transformation barrier from defective V₂O₅ toward VO₂. In the VO₂ phase, Mo doping modulates chemical properties of every oxygen atom, while doping in V₂O₅ only affects the oxygen atoms that directly bond with the dopants. Charge analysis indicated that the conductive nature of VO₂ delocalizes charge within the lattice and alters the overall chemical properties. Experiments confirmed that Mo-doped VO₂ is the dominant phase during the redox process, exhibiting the best catalytic performance. Hence, delocalization could be key to future chemical applications of efficiently doped materials.