Direct Conversion of Syngas into Light Olefins over Zirconium‐Doped Indium(III) Oxide and SAPO‐34 Bifunctional Catalysts: Design of Oxide Component and Construction of Reaction Network

Abstract

Abstract The direct synthesis of light olefins from syngas over a bifunctional catalyst containing an oxide and zeolite has been proven to be a promising strategy. Nevertheless, an unclear reaction network hinders any further enhancement in catalytic performance, such as increasing the conversion of CO. We herein report a novel bifunctional catalyst composed of a InZr binary oxide and SAPO‐34 zeolite displaying superior CO conversion (27.7 %) with selectivity to light olefins (73.6 %) at 400 °C, 2.0 MPa. We demonstrate that the Zr‐doped body‐centered cubic In 2 O 3 phase, exhibiting higher stability than pure In 2 O 3 under a reducing atmosphere, is the active oxide component for the initial activation of CO. A complete reaction network is proposed by DFT calculations and model reactions, revealing that CO activation over Zr‐In 2 O 3 follows a quasi‐CO 2 hydrogenation pathway and methanol is the key intermediate to be transformed into light olefins in zeolites. Moreover, inhibiting excessive hydrogenation is an effective strategy to achieve higher performance.