Redispersion of Pt nanoparticles encapsulated within ZSM-5 at high temperature oxygen for partial oxidation of methane

Active metal agglomeration in heterogeneous catalysis is a crucial reason of catalyst deactivation. Consequently, many methods to inhibit the sintering by redispersing metal course have been widely studied. However, the redispersion conditions of catalysts with different structures may also be different. In our work, we prepared Pt/ZSM-5 and Pt@ZSM-5 catalysts to study that the redispersion of Pt under different pretreatment conditions. Characterizations demonstrate that only Pt@ZSM-5 (4R, 5O) implements Pt redispersion. The redispersion of Pt nanoparticles is due to the encapsulation constraint of the ZSM-5 as well as Pt δ+ species migrate at 500℃ oxygen atmosphere, which are anchored to the -(-O-Si≡) y site in ZSM-5 by strong metal support interaction. Benefiting from highly dispersed active sites, Pt@ZSM-5 (4R, 5O) catalyst also shows excellently catalytic activity, stability and anti-carbon deposition ability in partial oxidation of methane (POM). The results provide ideas for the preparation of catalysts for high temperature oxidation reaction.