fig4

Figure 4. Data from response surface optimization and catalyst stability. The 3D surfaces show the effects of temperature-time (A); temperature-pressure (B), and time-pressure (C) parameters on the yield of 2a; The 2D contours show the effects of temperature-time (D); temperature-pressure (E); and time-pressure (F) parameters on the yield of 2a; (G) Heterogeneous catalytic behavior of Ru₁/o-CeO₂-ov catalyst (Reaction conditions: 1 mmol 1a, 0.3 mol% Ru₁/o-CeO₂-ov, 3 mL n-octane, 100 °C, 3 MPa H₂); (H) Ru₁/o-CeO₂-ov catalyst recycling study (Reaction conditions: 0.3 mol% Ru₁/o-CeO₂-ov for 1a, 3 mL n-octane, 100 °C, 3 MPa H₂, 3 h; Regeneration conditions refer to the process of preparing Ru₁/o-CeO₂-ov from Ru₁/o-CeO₂); (I) HAADF STEM image and EDS mappings of the Ru₁/o-CeO₂-ov catalyst after use. 2D: Two-dimensional; 3D: three-dimensional; HAADF STEM: high-angle annular dark field scanning transmission electron microscope; EDS: energy-dispersive X-ray spectrometer.