Publication (UFCHJH): Superior activity of non-interacting close acidic protons in Alrich Pt/H-*BEA zeolite in isomerization of n-hexane"

Abstract: Skeletal isomerization of linear alkanes, an essential reaction for the production of gasoline, relies onenvironmentally questionable chlorinated catalysts, whose activity exceeds that of alternative zeolitecatalysts. This work describes an attempt to understand relations between the local arrangement ofactive sites and skeletal isomerization of n-hexane in order to adapt the structure of zeolite catalyststo increase the reaction rates. For this purpose, we used a combination of synthesis of zeolites of*BEAstructural topology with unique density and distribution of strongly acid sites, analysis of the nature ofthe acid sites by1H MAS NMR spectroscopy and FTIR spectroscopy of the OH groups and adsorbed d3-acetonitrile, UV–vis-NIR spectroscopy of carbocations formed by protonization, and kinetic analysis. Wedemonstrate that the high density of non-interacting but close and strongly acidic structural hydroxylgroups significantly lower the activation barrier in the isomerization reaction compared to far-distantacid sites. The organotemplate-free synthesized Al-rich Pt/H-*BEA zeolite (Si/Al 4.2) with an unparalleledhigh concentration of the non-interacting close H+ions balancing the charge of the Al-Si-Al sequencesforming a wall between the two channels yields 6 times higher reaction rates compared to state-of-the-artSi-rich Pt/H-zeolite catalysts.

Sazama P., Kaucky D., Moravkova J., Pilar R., Klein P., Pastvova J., Tabor E., Sklenak S., Jakubec I., Mokrzycki L.: "Superior activity of non-interacting close acidic protons in Alrich Pt/H-*BEA zeolite in isomerization of n-hexane",  Applied Catalysis A: General DOI: 10.1016/j.apcata.(2016)12.016.

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