Highly active and stable Y2O3 promoted TiO2-ZrO2 catalyst for propane dehydrogenation

Abstract

The introduction of TiO2 has been proved to improve the reactivity of ZrO2 for propane dehydrogenation for the first time. The enhanced propane conversion for TiO2-2ZrO2 sample is mainly attributed to the increased number of active Zrcus sites and the corresponding oxygen vacancies. While the consequent excessive aciditypromoting secondary reactions is unfavorable for the selectivity to propene. Fortunately, the additionally doped Y2O3 increases both the conversion of propane and the selectivity to propene due to further incremental Zrcus sites and decreased acidity. The yield of propene remains at 34% for the optimal 5Y2O3/TiO2-2ZrO2 catalyst over the continuous 20 reaction-regeneration cycles. In addition, the adsorption mode of propane on the catalyst is determined to be a two-site mode with H atoms in methyl and methylene groups (di-σ-bonded propylene) using an in-situ FTIR technique, and the possible reaction route has also been speculated.