Fig. 1. (a) Morphologies of the Cu-Zn-Al-Zr-LDH precursor, calcined CuO-ZnO-Al2O3-ZrO2 composite oxide, and reduced Cu-ZnO-Al2O3-ZrO2 catalyst. Reproduced with permission from Ref. [22]. Copyright 2017, Elsevier. (b) Comparison of the CH3OH selectivity obtained by the unmodified and fluorine-modified Cu-ZnO-Al2O3-ZrO2 catalysts for CO2 hydrogenation. Inset: formation of fluorinated Cu-Zn-Al-Zr LDH achieved via the introduction of (AlF6)3- ions into layers. (c) Results of the stability test conducted on the Cu-ZnO-Al2O3-ZrO2 catalyst for CO2 hydrogenation to methanol derived from the phase-pure LDH precursor under the following reaction conditions: 250 °C, 5 MPa, 4000 h-1, and H2/CO2 = 3. Reproduced with permission from Refs. [21] and [28]. Copyright 2015 and 2016, Elsevier.

Fig. 2. (a) Schematic illustration of the most favorable CO2 hydrogenation pathways predicted to occur on the surface of cubic In2O3(110) [c-In2O3(110)], c-In2O3(111), hexagonal In2O3(012) [h-In2O3(012)], and h-In2O3(014). Effects of reaction temperature on the extent of CO2 conversion and CH3OH product selectivity (b) and on the CH3OH yield (c) in the reaction occurring over spherical c-In2O3 (c-In2O3-S) and h-In2O3 nanorod (h-In2O3-R) samples under the following reaction conditions: 300 °C, 5 MPa, 9000 mL gcat-1 h-1, and H2/CO2 = 3. (d) In situ diffuse reflectance infrared Fourier-transform spectroscopy data recorded for surface species formed from CO2 hydrogenation reaction occurring over h-In2O3-R. Reproduced with permission from Ref. [32]. Copyright 2020, Science.

Fig. 3. (a) Effect of the particle size of spent In2O3 (after reaction for 24 h) on the space-time yield of lower olefins from the CO2 hydrogenation reaction under the following reaction conditions: 350 °C, 3 MPa, 9000 mL gcat-1 h-1, and H2/CO2 = 3. Reproduced with permission from Ref. [40]. Copyright 2021 Elsevier. (b) High-resolution transmission electron microscopy images of In2O3 and In1-xZrxOy solid solution oxides. (c) CO2-TPD spectra for the reduced In2O3, ZrO2, and In1-xZrxOy oxides. (d) Energy profiles of the CO2 hydrogenation reaction to CH3OH conducted over the surfaces of In2O3 and In1-xZrxOy, reported in black and red, respectively. Reproduced with permission from Ref. [39]. Copyright 2018, American Chemical Society. (e) Effects of the crystal size and pore structure of the SAPO-34 zeolite on the C2=-C4= product selectivity and olefin/paraffin molecular ratio caused by the CO2 hydrogenation reaction conducted over bifunctional catalysts under the following reaction conditions of 380 °C, 3 MPa, 9000 mL gcat-1 h-1, and H2/CO2 = 3. Reproduced with permission from Ref. [42]. Copyright 2019, John Wiley and Sons.

Fig. 4. (a) Mechanism of the reaction of CO2 hydrogenation to produce aromatic compounds and isoparaffins occurring over the Na-Fe3O4/zeolite composite catalyst. Reproduced with permission from Ref. [67]. Copyright 2019, Royal Society of Chemistry. (b) Morphologies of hierarchical nanocrystalline HZSM-5 aggregates. Reproduced with permission from Ref. [34]. Copyright 2019, American Chemical Society. Transmission electron microscopy images of the short b-axis (c) and chain-like (d) nanocrystalline HZSM-5. (e) Proposed mechanism of the reaction of CO2 hydrogenation to produce aromatic compounds occurring over ZnZrOx/HZMS-5, and the effect of the acidic properties and pore structure of HZSM-5 on the distribution of the produced aromatic compounds. Reproduced with permission from Ref. [60]. Copyright 2021, Elsevier. (f) Catalytic performance of bifunctional catalysts and the sole In2O3 for the reaction of CO2 hydrogenation under the reaction conditions of 340 °C, 3 MPa, 9000 mL gcat-1 h-1, and H2/CO2 = 3, as well as CH3OH conversion over HZSM-5. Reproduced with permission from Ref. [38]. Copyright 2017, Springer Nature.

Fig. 5. (a) Effect of the proximity between the ZnZrOx and HZMS-5 components of the catalyst on system’s catalytic performance under the following reaction conditions: 315 °C, 3 MPa, 1020 mL gcat-1 h-1, and H2/CO2 = 3. (b) Product distribution without CO, CO2 conversion, and CO selectivity over ZnZrOx/HZMS-5 prepared by mixing ZnZrOx and HZSM-5 power by using an agate mortar with different reaction temperatures. Reproduced with permission from Ref. [60]. Copyright 2021, Elsevier. (c) Effect of the proximity between the In2O3 and HZMS-5 components of the catalyst on system’s catalytic performance under the reaction conditions detailed in Fig. 4(f). (d) Detail hydrocarbon distribution over In2O3/HZSM-5 prepared by mixing of granules (500-800 μm) of two components. Reproduced with permission from Ref. [38]. Copyright 2017, Springer Nature.

Fig. 6. Different catalyst systems reported in the literature for CO2-based Fischer-Tropsch synthesis and their main hydrocarbon products and typical selectivity values.