Facilitating CO2 dissociation via Fe doping on supported vanadium oxides for intensified oxidative dehydrogenation of propane.

The unique Fe-O-V structure in the dual-functional Fe-V mixed oxides catalyst promotes the formation of oxygen vacancies in the catalyst and accelerates the dissociation of CO 2 , which boost the cyclic replenishment of the lattice oxygen during the oxidative dehydrogenation of propane, and thereby achieving an enhanced catalytic performance. [Display omitted] • A dual-functional Fe-V mixed oxides was controllably synthesized over Al 2 O 3. • 5Fe-5V-Al 2 O 3 achieved a record-high C 3 H 6 yield in V-based CO 2 -ODP catalysts. • Fe sites in the unique Fe-O-V structure can accelerate the dissociation of CO 2. • CO 2 was dissociated into active oxygen species and supplemented lattice oxygen. Selective oxidative dehydrogenation of propane with CO 2 (CO 2 -ODP) represents a promising pathway of propylene production and CO 2 utilization. Presently, vanadium (V) based catalysts are commonly used due to the excellent redox ability originated from the multivalent V. However, the CO 2 -ODP reaction mechanism remains elusive, limiting the rational design of highly efficient catalytic systems. Herein, we introduced Fe into impregnated V-Al 2 O 3 to build a dual-sites catalyst including Fe and V, achieving a C 3 H 8 conversion at ∼43 % and C 3 H 6 selectivity exceed 80 %. Via regulating the Fe/V molar ratio, we clearly describe that the formation of unique Fe-O-V facilitated the CO 2 dissociation. Intrinsically, V is the main active site contributing for C 3 H 8 dehydrogenation while Fe site is responsible for the CO 2 dissociation, replenishing lattice oxygen to enhance oxidative dehydrogenation of C 3 H 8. The design of dual-sites catalyst and extraction of molecular understanding provide guidance for the rational development of highly active CO 2 -ODP catalysts. [ABSTRACT FROM AUTHOR]