In Situ Reconstruction of Active Heterointerface for Hydrocarbon Combustion through Thermal Aging over Strontium-Modified Co₃O₄ Nanocatalyst with Good Sintering Resistance

Abstract

The issue of catalyst deactivation due to sintering has gained significant attention alongside the rapid advancement of thermal catalysts. In this work, a simple Sr modification strategy was applied to achieve highly active Co 3 O 4 -based nanocatalyst for catalytic combustion of hydrocarbons with excellent antisintering feature. With the Co 1 Sr 0.3 catalyst achieving a 90% propane conversion temperature (T 90 ) of only 289 °C at a w8 hly space velocity of 60,000 mL•g −1 •h −1 , 24 °C lower than that of pure Co 3 O 4 . Moreover, the sintering resistance of Co 3 O 4 catalysts was greatly improved by SrCO 3 modification, and the T 90 over Co 1 Sr 0.3 just increased from 289 to 337 °C after thermal aging at 750 °C for 100 h, while that over pure Co 3 O 4 catalysts increased from 313 to 412 °C. Through strontium modification, a certain amount of SrCO 3 was introduced on the Co 3 O 4 catalyst, which can serve as a physical barrier during the thermal aging process and further formation of Sr−Co perovskite nanocrystals, thus preventing the aggregation growth of Co 3 O 4 nanocrystals and generating new active SrCoO 2.52 −Co 3 O 4 heterointerface. In addition, propane durability tests of the Co 1 Sr 0.3 catalysts showed strong water vapor resistance and stability, as well as excellent low-temperature activity and resistance to sintering in the oxidation reactions of other typical hydrocarbons such as toluene and propylene. This study provides a general strategy for achieving thermal catalysts by perfectly combining both highly low-temperature activity and sintering resistance, which will have great significance in practical applications for replacing precious materials with comparative features.