CO₂-assisted oxidative dehydrogenation of propane catalyzed by Fe modified vanadium oxide/silicalite-1 catalysts

CO₂-assisted oxidative dehydrogenation of propane (CO₂-ODP) is a very promising alternative strategy to boost propylene production and reaction stability. VO_x-based catalysts have attracted much attention due to their high lattice oxygen activity and unique redox capacity. However, the CO₂ introduced during the CO₂-ODP tends to undergo competitive reaction with C₃H₈, leading to undesirable C₃H₈ conversion. It remains a great challenge to develop more efficient catalytic systems to accelerate C₃H₈/CO₂ adsorption and activation. In this work, we investigated the performance of Fe-modified vanadium oxide/silicalite-1 (VO_x/S-1) catalyst, in which the introduction of Fe not only promotes CO₂ activation and dissociation, but also increases the weakly acidic and basic sites of the catalyst, ultimately accelerating the reverse water–gas shift reaction. In addition, the 10V-0.5Fe/S-1 catalyst possesses more highly dispersed isolated VO₄³⁻ and more active V⁴⁺ species. As a result, the initial C₃H₈ yield and CO₂ conversion of 10V-0.5Fe/S-1 catalyst are improved to 46.2 % and 37.8 % at WHSV = 1.6 h⁻¹, which gives an excellent performance among the majority of nonprecious-metal based catalysts reported in the last five years. The bimetallic-site 10V-0.5Fe/S-1 catalyst provides guidance for the rational development of highly active CO₂-ODP catalysts.