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During the second year, we continue to employed large-scale first-principles quantum mechanical calculations to investigate the catalytic chemical reaction of the dehydrogenation of a selected alkane, propane (C₃H₈), with the presence of Cr (in the form of dispersed chromium oxide CrO₃ species) supported on g-alumina (g-Al₂O₃). We used the model of periodic supercells and the method of density-functional theory with ultrasoft pseudopotentials, the generalized gradient-corrected exchange-correlation functionals, and the plane-wave basis set.

We reported in the first annual report that we found that when a propane (C₃H₈) molecule reacts with to a CrO₄ species supported on the γ-Al₂O₃ surface, dissociation of propane occurs - two hydrogen atoms of the C₃H₈ molecule are trapped by the oxygen sites of the chrominm oxide species, and a propene (C₃H₆) molecule is simultaneously released. In the second year (the period covering this report), we investigated the role of a CrO₃ species supported on the γ-Al₂O₃ surface and we found CrO₃ acts as a catalyst in a way similar to the CrO₄ species – the dissociation of C₃H₈ molecule (into a C₃H₆ molecule and two trapped hydrogen atoms) with the presence of CrO₃/γ-Al₂O₃ is energetically favorable, and the energy gain is of ~0.2–1.1 eV.

However, the activation energy of the dissociation process has not yet determined. We are currently employing “nudged elastic band method” to determine the reaction pathways and the associated reaction barriers of dehydrogenation of propane. We expect to report the results in the next report.*

* This project was initially awarded for two years, but we requested for a no-cost extension, and a one-year extension was approved by PRF.