Theoretical investigation on structural effects of Pt–Mn catalyst on activity and selectivity for methylcyclohexane dehydrogenation

• Published in: Chemical physics letters Vol. 711; pp. 73 - 76
• Main Authors: Manabe, Shota, Yabe, Tomohiro, Nakano, Atsushi, Nagatake, Satoshi, Higo, Takuma, Ogo, Shuhei, Nakai, Hiromi, Sekine, Yasushi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2018
• Subjects: Dehydrogenation of methylcyclohexane; DFT; Hydrogen carrier; Unsaturated coordination; XAFS; DFT; Hydrogen carrier; Unsaturated coordination; Dehydrogenation of methylcyclohexane; XAFS
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2018.09.026

[Display omitted] •Catalytic dehydrogenation of methylcyclohexane (MCH) was investigated.•Mn addition on Pt/Al2O3 catalyst brought higher activity, selectivity and stability.•Effect of catalyst structure was investigated by experimentally and theoretically.•Demethylation easily proceeds on the unsaturated step facets of Pt.•Mn addition brought selective dehydrogenation of MCH by coverage of such sites. The structure of Pt-Mn/Al2O3 catalyst which shows high performance for dehydrogenation of methylcyclohexane, a prospective hydrogen carrier, was investigated by XAFS and DFT calculations. Mn addition on Pt/Al2O3 brings higher activity, selectivity, and stability for dehydrogenation of MCH than with Pt/Al2O3 alone. Results of XAFS and DFT calculations revealed that MnOx selectively covered the unsaturated coordination of Pt. On the unsaturated step facets such as Pt (1 1 0) and Pt (3 1 1), demethylation proceeds easily. Addition of Mn on Pt/Al2O3 catalyst brought selective dehydrogenation of MCH by coverage of such step sites with MnOx.