ZrO2-based unconventional catalysts for non-oxidative propane dehydrogenation: Factors determining catalytic activity

Non-oxidative propane dehydrogenation (PDH) was investigated over unconventional catalysts, i.e. binary La2O3-ZrO2 and Y2O3-ZrO2 materials with or without tiny amounts (0.005 or 0.05 wt.%) of Ru in form of nanoparticles with the size of about 1.1 nm. The results of catalytic tests and catalyst characterization with complementary techniques enabled us to conclude that coordinatively unsaturated zirconium cations (Zr-cus) and neighboring lattice oxygen are catalytically active sites responsible for C3H6 formation. Supported Ru species contribute to a minor extent to PDH but promote generation of Zrcus sites upon catalyst reductive treatment or in situ under PDH conditions. The concentration of Zr. sites can also be increased through doping of ZrO2 with La2O3 or Y2O3 with the latter being a more efficient dopant.(.)High activity, selectivity, and durability of our catalysts were verified by comparing their performance under industrially relevant conditions with that of a conventional K-CrOx/Al2O3 reference material in a series of 60 PDH/oxidative regeneration cycles at 550, 600, and 625 degrees C. (C) 2017 Elsevier Inc. All rights reserved.