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-Al2O3) with rich unsaturated pentacoordinate Al3+ sites stabilizing Ru-CeOx catalysts were designed and synthesized for catalytic total oxidation of one typical light alkanes (propane, C3H8). The 90 % conversion temperature (T-90) and the apparent activation energy (Ea) of Ru-Ce-7/NF-Al2O3 modified by 7 wt.% of CeO2 were as low as 207 degrees 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-CeOx/NF-Al2O3 is mainly attributed to NF-Al2O3 has rich unsaturated pentacoordinate Al3+ sites can anchor the Ru-CeOx active species. The anchoring effect of Al-penta(3+) on the metal active unit can effectively promote the dispersion of Ru-CeOx active species and stabilize the electronic valence state of Ru-0. The degradation of C3H8 over Ru-CeOx/NF-Al2O3 conformed to the Mars-vanKrevelen mechanism through two different pathways as revealed by the in situ DRIFTS.

Automated summary

A series of nano-flower sheet-like alumina spheres were designed and synthesized to stabilize Ru-CeOx catalysts for the catalytic total oxidation of propane. The material exhibited low conversion temperature and activation energy, as well as superior resistance to water, sulfur, and carbon dioxide, along with good recycling performance. The excellent catalytic performance is attributed to the rich unsaturated pentacoordinate Al3+ sites on the NF-Al2O3 material, which anchor the Ru-CeOx active species and promote dispersion and stability.