Highly Selective Synthesis Isoparaffins from CO 2 Hydrogenation over ZSM‐5@ZnCr Reverse Capsule Catalyst

Abstract The traditional oxide@zeolite capsule catalysts, which metal oxide as core and zeolite as shell, have been demonstrated to effectively tune the product selectivity in CO/CO 2 hydrogenation to chemicals or fuels. However, developing a practical method for preparing capsule catalyst with small and uniform particle size remained challenging. Herein, we constructed a “reverse” ZSM‐5@ZnCr capsule catalyst for CO 2 hydrogenation to isoparaffins with high selectivity, where ZSM‐5 zeolite as the core and ZnCr oxide as the shell. It was worth noting that this uniformly sized (approximately 4.5 µm) reverse capsule catalyst was prepared by a facile modified co‐precipitation method. In this catalytic system, ZnCr not only converted CO 2 into methanol, but also played a crucial role for iso‐olefins hydrogenation to isoparaffins, where iso‐olefins were obtained from methanol transformation on zeolite. At 360 °C and 5 M Pa, the isoparaffins selectivity in hydrocarbons approached 75.6% at 17.3% CO 2 conversion. Furthermore, the ZSM‐5@ZnCr capsule catalyst exhibited excellent stability during 100 h on stream, while CO 2 conversion and isoparaffins selectivity kept nearly unchanged. This work provides a promising strategy for designing efficient catalysts for CO 2 conversion.