Insights into flower-like Al2O3 spheres with rich unsaturated pentacoordinate Al3+ sites stabilizing Ru-CeOx for propane total oxidation

Herein, a series of nano-flower sheet-like alumina spheres (NF-Al 2 O 3 ) with rich unsaturated pentacoordinate Al 3+ sites stabilizing Ru-CeO x catalysts were designed and synthesized for catalytic total oxidation of one typical light alkanes (propane, C 3 H 8 ). The 90 % conversion temperature (T 90 ) and the apparent activation energy (Ea) of Ru-Ce 7 /NF-Al 2 O 3 modified by 7 wt.% of CeO 2 were as low as 207 °C and 56.7 kJ mol −1 , respectively. In addition, it also exhibited superior water, sulfur and carbon dioxide resistance and recycling performance. The excellent catalytic performance of propane total oxidation over Ru-CeO x /NF-Al 2 O 3 is mainly attributed to NF-Al 2 O 3 has rich unsaturated pentacoordinate Al 3+ sites can anchor the Ru-CeO x active species. The anchoring effect of Al 3+ penta on the metal active unit can effectively promote the dispersion of Ru-CeO x active species and stabilize the electronic valence state of Ru 0 . The degradation of C 3 H 8 over Ru-CeO x /NF-Al 2 O 3 conformed to the Mars-van-Krevelen mechanism through two different pathways as revealed by the in situ DRIFTS.