First-principles analysis of propane dehydrogenation over chromium oxide catalysts

The Bizeolcat’s partners from the Kemijski Inštitut (Slovenia) have recently calculated the entire reaction network for the propane dehydrogenation over chromium oxide catalysts. The DFT+U approach was used to account for strong correlation of Cr and Cr2O3(0001) surface was selected as the most stable one. The entire reaction network consists of 15 elementary reactions, which are shown in Figure 1.

Figure 1: Reaction mechanism (all elementary reaction steps shown) for propane dehydrogenation over Cr2O3(0001).

The calculated reaction potential surface is in Figure 2. Kinetic modelling using kinetic Monte Carlo has also been performed. Using these data, we show that the reaction proceeds through the intermediates CH3CH2CH3, CH3CHCH3, CH3CHCH2 and does not proceed to propyne at normal operating conditions (850 K, 1.5 atm, non-oxidative).

Hydrogen is formed as a side-product.

Figure 2: Potential energy surface for propane dehydrogenation over Cr2O3(0001)

These results are reported in a scientific paper, which is under review at the moment. A subset of these data has also been presented at two international conferences: Slovenian Chemical Days in Maribor (September 2019) and Quantum Espresso Summer School on Advanced Materials and Molecular Modelling (September 2019).