Significant increase of specific target olefin selectivity in CO_(2)hydrogenation is not only scientifically interesting but also practically valuable because of the reduction of separation cost.Here,a new composite c...Significant increase of specific target olefin selectivity in CO_(2)hydrogenation is not only scientifically interesting but also practically valuable because of the reduction of separation cost.Here,a new composite catalyst is fabricated with surface oxygen vacancy-abundant ZnZrO_(x)(H)solid solution and ultra-small H-SAPO-34(US)molecular sieve crystals.This catalyst shows a propene selectivity in hydrocarbons of 51.2%that accounts for about 63%of light olefins,along with a CO_(2)conversion of 13.5%,at 350°C and 3.0 MPa.A combination of in situ spectroscopy,isotope-labelled experiments,DFT calculations,and AIMD simulations reveals that an increase of surface oxygen vacancies in ZnZrO_(x)(H)induces formation of a coordinatively unsaturated(Zr-O)_(n)-Zn-(Ov)_(m)configuration,which elevates Zn site electron density and enhances the electronic interaction of Zn-3d and H-1s orbitals.This promotes the H_(2)dissociation and facilitates methanol intermediate formation.The ultra-small H-SAPO-34(US)crystals with a size of 100–200 nm effectively suppresses alkenes hydrogenation and subsequent aromatization in the methanol conversion process.As a result,more propene was produced.展开更多
基金supported by the National Key R&D Program of China(2023YFB4103102)National Natural Science Foundation of China(21991090,21991092,22322208,22272195,U22A20431)+2 种基金the Basic Research Program of Shanxi Province of China(202203021224009)Innovation foundation of Institute of Coal Chemistry,Chinese Academy of Sciences(SCJC-DT-2023-06)Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS)(2021172).
文摘Significant increase of specific target olefin selectivity in CO_(2)hydrogenation is not only scientifically interesting but also practically valuable because of the reduction of separation cost.Here,a new composite catalyst is fabricated with surface oxygen vacancy-abundant ZnZrO_(x)(H)solid solution and ultra-small H-SAPO-34(US)molecular sieve crystals.This catalyst shows a propene selectivity in hydrocarbons of 51.2%that accounts for about 63%of light olefins,along with a CO_(2)conversion of 13.5%,at 350°C and 3.0 MPa.A combination of in situ spectroscopy,isotope-labelled experiments,DFT calculations,and AIMD simulations reveals that an increase of surface oxygen vacancies in ZnZrO_(x)(H)induces formation of a coordinatively unsaturated(Zr-O)_(n)-Zn-(Ov)_(m)configuration,which elevates Zn site electron density and enhances the electronic interaction of Zn-3d and H-1s orbitals.This promotes the H_(2)dissociation and facilitates methanol intermediate formation.The ultra-small H-SAPO-34(US)crystals with a size of 100–200 nm effectively suppresses alkenes hydrogenation and subsequent aromatization in the methanol conversion process.As a result,more propene was produced.
