A novel synergetic effect between Ru and Cu nanoparticles for Ru-Cu/Al2O3 causes highly efficient photothermocatalytic CO2 reduction with good durability

Photothermocatalytic Dry Reforming of Methane for Efficient CO2 Reduction and Solar Energy Storage

“…This indicates that the oxidation of carbon species is accelerated by the photoactivation, thus improving the catalytic activity . A similar phenomenon for CO 2 -TPO-C was also observed on Ru–Cu/Al 2 O 3 …”

“…A similar enhancement in catalytic activity upon focused illumination is observed for DRM on Rh–Au/SBA-15, Pt/black TiO 2 , MgO/Pt/Zn–CeO 2 , Pt/Si–CeO 2 , Ni/CeO 2 , Co/Co–Al 2 O 3 , SCM-Ni/SiO 2 , Ni/Ni–Al 2 O 3 , Ni–La 2 O 3 /SiO 2 , Ru–Cu/Al 2 O 3 , and Ni/Mg–Al 2 O 3 . For the catalysts using insulator oxides as supports, light-induced enhancement in catalytic activity is mainly attributed to the photoactivation on Co and Ni nanoparticles as discussed above. ,,, But for Pt/Al 2 O 3 and Pt/SiO 2 , no obvious light-induced enhancement in catalytic activity is observed. , For the catalysts using semiconductor metal oxides (e.g., black TiO 2 , CeO 2 , Zn–CeO 2 , Si–CeO 2 ) as supports of Pt nanoparticles for photothermocatalytic DRM, ,, the catalytic enhancement upon focused illumination at high temperature (below 350 °C, all the catalysts have no catalytic activity for DRM) is explained to arise from the contribution of photocatalysis on the semiconductor photocatalysts, in which photogenerated electrons participate in CO 2 reduction while photogenerated holes participate in CH 4 oxidation. , In this case, three mechanisms, such as light-driven thermocatalytic DRM on Pt nanoparticles, light-driven thermocatalytic DRM on semiconductor metal oxides (e.g., TiO 2 , CeO 2 ) (as the metal oxides have thermocatalytic activity for DRM at high temperature), and photocatalytic DRM on the semiconductor metal oxides, simultaneously occur.…”

“…Under focused UV–vis–IR illumination, Cu/Al 2 O 3 demonstrates very low catalytic activity. In contrast, however, Ru–Cu/Al 2 O 3 has high r H2 and r CO values of 56.72 and 63.20 mmol min –1 g –1 owing to the combination of the high catalytic activity of Ru nanoparticles and the strong surface plasmonic absorption of Cu nanoparticles …”

“…123 A similar phenomenon for CO 2 -TPO-C was also observed on Ru−Cu/Al 2 O 3 . 108 Very recently, Zhou et al reported a substantial increase in catalytic activity for DRM on Cu 19.8 Ru 0.2 upon focused UV− vis−IR illumination as compared to thermocatalytic DRM at the same reaction temperature. 91 The initial thermocatalytic r CH4 value at 727 °C in the dark is ∼60 μmol g −1 s −1 (Figure 12A).…”

“…The enhancement is attributed to the integration of Zn doping and surface modification by MgO that produce passivated surface states and defects, thus accelerating charge carriers' separation and providing more charge carriers which participate in the activation of CH 4 and CO 2 . 106 108 However, because precious metals are earth-scarce and very expensive, designing a nonprecious metal catalyst is highly desirable. Aimed at the target, a composite of Ni nanocrystals (with average particle size of 16.4 nm) closely contacted to CeO 2 nanocrystals (Ni/CeO 2 ) was prepared.…”