fig4

Figure 4. (A) Capillary flow reactor results for the calcined 10 mol% Cu-HAP catalyst. The conversion rates and activation energies, recorded under dark and light conditions, for the selective hydrogenation of CO₂ to CO are plotted. Reproduced from Ref.^[133] with permission from American Chemical Society. (B) Photocatalytic reverse-WGS activity of calcined Cu-HAP samples as a function of Cu content in a batch reactor. Reaction conditions: H₂/CO₂ ratio = 1:1, light intensity = 40 suns, no external heating, and measurement time = 1 h. Reproduced from Ref.^[133] with permission from American Chemical Society. (C) CH₄ conversion for Ni/xLa-HAP catalysts. Reaction condition: CH₄:CO₂ = 1:1, catalyst weight = 100 mg, total flow rate = 40 mL/min, reaction temperature = 750 °C, GHSV = 24,000 mL/g·h. Adapted from Ref.^[150] with permission from Elsevier. (D) Schematic of possible reaction pathways in DRM for La-substituted and pristine Ni/HAP. Adapted from Ref.^[150] with permission from Elsevier.