Fig. 1.
Catalytic performance for CO2 hydrogenation. a The effect of space velocity over ZnAlOx&H-ZSM-5. Reaction conditions: 593 K, 3.0 MPa, H2/CO2/Ar = 3/1/0.2. b Comparisons of the CO2 conversion and product selectivity over various catalysts. Reaction conditions: Space velocity = 12,000 (for ZnO and ZnAlOx) or 6000 (for composite catalysts) ml g−1 h−1, 3.0 MPa, 593 K, H2/CO2/Ar = 3/1/0.2. Note that the C5+ excludes aromatics. C2-4= and C2-4o refer to C2–C4 olefins and paraffins, respectively; ZnAlOx&H-ZSM-5 prepared by grinding; ZnAlOx + H-ZSM-5 prepared by granules mixing; ZnAlOx/H-ZSM-5 denoted as dual-bed catalysts