Enhanced Antioxidation Stability of Iron-Based Catalysts via Surface Decoration with ppm Platinum

Enhanced stability of iron-based catalysts by noble metals has been previously reported. To further understand the efficiency of precious metals in preventing the Fe surface from being oxidized, we synthesized a series of Pt-doped Fe catalysts with controlled amounts of Pt decoration on the Fe surface using one-pot hydrolysis and co-condensation of inorganic salts, which were then studied in the hydrodeoxygenation (HDO) of m-cresol. The results showed that the addition of Pt could significantly improve the catalyst activity and stability in the HDO of m-cresol. A minimum Pt/Fe atomic ratio of 1/13 was found to maintain the Fe stability, implying that Pt has an ensembled effect on Fe or Pt atoms to stabilize neighboring Fe atoms. In particular, a 0.05Pt–Fe catalyst with a trace amount of Pt (50 ppm or 0.05 wt % Pt) showed excellent stability without oxidation for 40 h time-on-stream even in the presence of H2O. This work illustrates that the activity and stability of earth abundant Fe-based catalysts can be improved with ppm precious metals