Fe-MOF Materials as Precursors for the Catalytic Dehydrogenationof Isobutane

We investigate the use of a series of iron-basedmetal-organic frameworks as precursors for the manufacturing ofisobutane dehydrogenation catalysts. Both the as-prepared andspent catalysts were characterized by PXRD, XPS, PDF, ICP-OES,and CHNS+O to determine the physicochemical properties of thematerials and the active phases responsible for the catalytic activity.In contrast to the previous literature, our results indicate that (i)the formation of metallic Fe under reaction conditions results insecondary cracking and coke formation; (ii) the formation of ironcarbide only contributes to coke formation; and (iii) thestabilization of the Fe2+species is paramount to achieve stableand selective catalysts. In this sense, promotion with potassium and incorporation of titanium improve the catalytic performance.While potassium is well known to improve the selectivity in iron-catalyzed dehydrogenation reactions, the unprecedented effect oftitanium in the stabilization of a nanometric titanomaghemite phase, even under reductive reaction conditions, results in amoderately active and highly selective catalyst for several hours on stream with a remarkable resistance to coke formation.

Automated summary

We investigated the use of iron-based metal-organic frameworks as precursors for isobutane dehydrogenation catalysts and characterized the materials to determine their properties and active phases. The stabilization of Fe2+ species is crucial for achieving stable and selective catalysts, and the addition of potassium and titanium can improve the catalytic performance.