High temperature reductive treatment promotes thermal stability of Pt/hexaaluminate catalysts for CO and C3H8 oxidation

Promoting the thermal stability of supported noble metal catalysts under harsh conditions remains challenging for the modern chemistry industry. Herein, Fe-substituted hexaaluminate supported Pt catalysts (Pt/BaFeAl11O19) were synthesized and treated with high temperature at 800 °C under different atmospheres. The Pt particles showed severe sintering under an oxidative atmosphere but high stability under reductive conditions. Interestingly, Pt/BaFeAl11O19 pre-reduced at high temperature possessed improved anti-sintering ablility during oxidative annealing. The characterization results demonstrate that oxygen vacancies were facilely formed under an H2 atmosphere to favor the formation of coating layers on Pt nanoparticles. This structure helps retain oxygen vacancies during subsequent oxidative calcination, contributing to promoted stability. The high thermal stability of Pt particles coupled with the easy generation of Fe2+ sites in Pt/BaFeAl11O19 resulted in excellent catalytic performance for CO and C3H8 oxidation after cycling hydrothermal aging at 800 °C.