fig3

Figure 3. (A) Reaction scheme for n-butanol/ethanol dehydration and butene isomerization pathways in H-ZSM-5. (A) is reprinted with permission from Ref.^[60], Copyright © 2024 Royal Society of Chemistry; (B) Simplified reaction scheme for the HAS over the CoCu catalyst. (B) is reprinted with permission from Ref.^[62], Copyright © 2022 American Chemical Society; (C) Powder XRD analysis of the spent catalysts after CO hydrogenation at 20 bar-60 bar and 200-380 °C after passivation at room temperature with air. The complete pattern is visualized in (a), with the dark grey bars corresponding to the Cu (ccp) reference and the black bars corresponding to the ZnAl₂O₄ reference. The resulting quantification of the assigned phases by a Rietveld refinement is shown in (b). (c) Compositional dependence of the cell parameter and domain size of the spinel phase. (d) The ccp phase shows a significant expansion of the cell parameter with the copper content x. The red line is a linear fit to all data points; the dashed lines indicate the lattice parameters for bulk ccp Cu and Co taken from several entries of the ICSD (#627115, 627114, 622435, 44989). The apparent domain size shows a drastic initial decrease upon addition of copper in the catalyst system. (C) is reprinted with permission from Ref.^[65], Copyright © 2022 Wiley-VCH GmbH; (D) Catalytic performance of CuCo catalysts varying Cu/Co ratio. (a) Catalytic performance of CuCo catalysts varying Cu/Co ratio; (b) Schematic diagram of “Seesaw” phenomenon [Note: the red and black arrows in (b)] represent the decrease and increase in Cu/Co ratio, respectively. (D) is reprinted with permission from Ref.^[68], Copyright © 2024 MDPI. XRD: X-ray diffraction analysis.