Vinyl alcohol formation via catalytic β-dehydrogenation of ethanol on Ir(100)

Insights and Activation Energy Surface of the Dehydrogenation of C2HxO Species in Ethanol Oxidation Reaction on Ir(100)

“…[75] In what follows, we will present the DFT results of dehydrogenation of C 2 H 5 O species, followed by Among the eight dehydrogenation pathways in the C 2 H 5 O species, six of them were studied previously. [40,70] The remaining two, β-dehydrogenation of CH 3 CH 2 O and CH 3 CHOH, were calculated in this work and the activation energy and reaction energy are provided in Table 1 and the structures of the reactants, transition states, and the products of these reactions are depicted in Figure 1. As shown in OH is the most preferred product kinetically.…”

“…These three dehydrogenation pathways on Ir(100) were studied previously. [70] It is interesting that the β-dehydrogenation was found to have the lowest activation energy barrier, although it is often the most difficult dehydrogenation, such as on a hydrogen boride sheet using in situ infrared absorption spectroscopy. [75] In what follows, we will present the DFT results of dehydrogenation of C 2 H 5 O species, followed by Among the eight dehydrogenation pathways in the C 2 H 5 O species, six of them were studied previously.…”

“…The H α removal of CH 2 CH 2 OH to form vinyl alcohol is the most favored pathway thermodynamically and kinetically. [70] Throughout the dehydrogenation of the C 2 H x O species with the DoDH up to 16.7 %, i. e. reactions 1-11, β-dehydrogenation is a dominant pathway for CH 3 CH 2 OH and CH 3 CHOH species and α-dehydrogenation is preferred for the CH 2 CH 2 OH and CH 3 CH 2 O species. Interestingly, even though the H β in CH 3 CH 2 OH and CH 3 CHOH is the further away from the Ir(100) surface with respect to the other two types of H atoms, the corresponding β-dehydrogenation pathways still exhibit lower energy barriers than the other dehydrogenation pathways.…”

“…The above model catalyst and the computational techniques are the same as those used in our studies of the other 18 dehydrogenation reactions of EOR. [40,70,76,82] We summarize below the numerical details of the DFT calculations.…”

“…Therefore, studying CÀ H activation [69] and expanding dehydrogenation reaction network beyond minimum energy pathway computationally are important for advancing our understanding of dehydrogenation in EOR. In addition to Pt, [36] dehydrogenation of ethanol on Ir was another system that is the most extensively studied, [40,70] which counts for 18 dehydrogenation steps of a total of 46. Additionally, Ir nanoparticles were also found to be specifically interesting in catalysis.…”