Steam reforming of toluene as model compound of biomass tar over Ni-Co/La2O3 nano-catalysts: Synergy of Ni and Co

A series of LaNi1-xCoxO3 (x = 0, 0.2, 0.5, 0.8 and 1) perovskite catalysts were prepared successfully and applied for toluene steam reforming as a model tar molecule. The Ni-Co alloy formation in reduced LaNi1-xCoxO3 was confirmed by TPR, XRD and XPS. The stronginteraction in LaNi0.8Co0.2O3 between Ni and Co produced highly dispersed and smaller metal (8-9 nm), higher reducibility and larger amounts of active sites as well as more abundant oxygen defects and higher surface/lattice oxygen mobility, confirmed by XRD, TEM, TPR, XPS and O-2-TPD. Also, a higher electron density prevented Ni from oxidation and sintering; a more oxidized Co (Co3+) facilitated the dissociation of water and activation of CO2, thus removing the coke. At 600 degrees C, S/C = 3.4 and WHSV = 16.56 ml h(-1) g(cat)(-1), an equilibrium conversion was achieved initially and over 80% conversion after 24 h were obtained for LaNi0.8Co0.2O3 with a high H-2 yield (81.8% at maximum) and 8.0 of H-2/CO ratio. The graphitic/filamentous coke formation was alleviated and no metal sintering was presented after the reaction. (C) 2021 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

Automated summary

A series of LaNi1-xCoxO3 perovskite catalysts were successfully prepared and applied in toluene steam reforming, with LaNi0.8Co0.2O3 showing excellent performance due to the strong interaction between Ni and Co leading to highly dispersed metal, higher reducibility, and abundant active sites.