Co-aromatization of methane and hexane over Pt encapsulated in ZSM-5 zeolite and the electronic effect of K promoters

This study is led by Prof. Peng He and Prof. Yong Yang (Institute of Coal Chemistry, Chinese Academy of Sciences). They encapsulated Pt within MFI-type zeolite to catalyze the co-aromatization of methane and hexane. The study meticulously investigates the effect of K promoters on the size and electron structure of Pt subnanocluster, highlighting their crucial role in achieving a high aromatic yield.

“To determine the proportion of Pt species encapsulated within the MFI particles, we utilized olefins molecules of varying sizes as probes. The characterization of the Pt cluster involved XPS analysis after etching the zeolite with argon and FTIR following CO adsorption. These experimental results, alongside DFT theoretical calculations, shed light on the electron structure of Pt. In addition to Pt, the reaction intermediates encapsulated by the zeolite structure were also examined. Hence, solid-state NMR was employed to investigate the species adsorbed within the zeolite channels. By labeling methane with ¹³C, we were able to reveal its role during the aromatization process.” Peng says.

The study found that K promoters not only facilitate the encapsulation of Pt subnanoclusters within the MFI channels but also modulate the electron density around the Pt atoms. These geometric and electronic modifications substantially boost the catalytic performance, leading to an aromatic selectivity of as high as 82%. Additionally, the inclusion of K promoters significantly enhances the involvement of methane in the reaction process.

See the article:

Co-aromatization of methane and hexane over Pt encapsulated in ZSM-5 zeolite and the electronic effect of K promoters

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