Single Mo Atoms Stabilized on High-Entropy Perovskite Oxide: A Frontier for Aerobic Oxidative Desulfurization

A single-site Mo-supported HEPO LaMn0.2Fe0.2Co0.2Ni0.2Cu0.2O3 with abundant mesoporous structures was initiated bya sacrificial-templatesynthesis protocol, which exhibits robust recycling stability andexceptional activity for the catalytic oxidation of DBT and its derivatives. The design and preparation of catalysts with both excellentstabilityand maximum exposure of catalytic active sites is highly desirable;however, it remains challenging in heterogeneous catalysis. Herein,a entropy-stabilized single-site Mo catalyst via a high-entropy perovskiteoxide LaMn0.2Fe0.2Co0.2Ni0.2Cu0.2O3 (HEPO) with abundant mesoporous structureswas initiated by a sacrificial-template strategy. The presence ofelectrostatic interaction between graphene oxide and metal precursorseffectively inhibits the agglomeration of precursor nanoparticlesin a high-temperature calcination process, thereby endowing the atomicallydispersed Mo6+ coordinated with four O atoms on the defectivesites of HEPO. The unique structure of single-site Mo atoms'random distribution with an atomic scale greatly enriches the oxygenvacancy and increases surface exposure of the catalytic active siteson the Mo/HEPO-SAC catalyst. As a result, the obtained Mo/HEPO-SACexhibits robust recycling stability and ultra-high oxidation activity(turnover frequency = 3.28 x 10(-2)) for thecatalytic removal of dibenzothiophene (DBT) with air as the oxidant,which represents the top level and is strikingly higher than the state-of-the-artoxidation desulfurization catalysts reported previously under thesame or similar reaction conditions. Therefore, the finding here forthe first time expands the application of single-atom Mo-supportedHEPO materials into the field of ultra-deep oxidative desulfurization.