2-Propanol Interacting with Co3O4(001):A combined AIMD and vSFS study

Abstract

The interaction of 2-propanol with Co3O4(001) was studied by vibrational sum fre-quency spectroscopy (vSFS) and by ab initio molecular dynamics (AIMD) simulations of 2-propanol dissolved in a water film to gain insight at the molecular level into the pathways of catalytic oxidation. The experimental study has been performed under near ambient condition, where the presence of water vapor is unavoidable, resulting in a water film on the sample and thereby allowing us to mimic the solution-water interface. Both experiment and theory conclude that 2-propanol adsorbs molecularly. The lack of dissociation is attributed to the adsorption geometry of 2-propanol in which the O-H bond does not point towards the surface. Furthermore, the copresent water not only competitively adsorbs on the surface but also inhibits 2-propanol deprotonation. The calculations reveal that the presence of water deactivates the lattice oxygen, thereby reducing the surface activity. This finding sheds light on the multifaceted role of water at the interface for the electrochemical oxidation of 2-propanol in aqueous solution as recently reported. At higher temperatures 2-propanol remains molecularly adsorbedon Co3O4(001) until it desorbs with increasing surface temperature.

Investigation of the effect of thermal annealing of Ni-cobaltite nanoparticles on their structure, electronic properties and performance as catalysts for the total oxidation of dimethyl ether

“…This material system was used to describe the interaction of the pure and chemically modified (Fe-doped) Co 3 O 4 (001) surfaces with water and alcohols, in good agreement with the experimental observations. [79][80][81][82][83][84][85] Vacancy stability. Oxygen vacancies play a key role in oxidation processes.…”

Co3O4 (111) surfaces in contact with water: Molecular dynamics study of the surface chemistry and structure at room temperature

“…The prominent (111) facet which is found to be very active in many processes like for example the activation of 2-propanol. 8 Co3O4 nanohexagons exposing the (111) facets can be synthesized using hydrothermal routes. 9,10 In such processes, water can play a controversial role as it could destabilize [11][12] or stabilize co-adsorbed species.…”

“…8 Co3O4 nanohexagons exposing the (111) facets can be synthesized using hydrothermal routes. 9,10 In such processes, water can play a controversial role as it could destabilize [11][12] or stabilize co-adsorbed species. [13][14][15] However, compared to the (001) and (101) that were studied at different coverage regimes, [16][17][18][19] the interaction of water with the Co3O4 (111) has not been studied to an extend that would allow a fundamental understanding of its role on the catalytic activity.…”

Co3O4 (111) surfaces in contact with water: molecular dynamics study of the surface chemistry and structure at room temperature

“…The prominent (111) facet is found to be very active in many processes like for example the activation of 2-propanol. 8 Co 3 O 4 nano-hexagons exposing the (111) facets can be synthesized using hydrothermal routes. 9,10 In such processes, water can play a controversial role as it could destabilize 11,12 or stabilize co-adsorbed species.…”

“…8 Co 3 O 4 nano-hexagons exposing the (111) facets can be synthesized using hydrothermal routes. 9,10 In such processes, water can play a controversial role as it could destabilize 11,12 or stabilize co-adsorbed species. [13][14][15] However, compared to the (001) and (101) facets that were studied at different coverage regimes, [16][17][18][19] the interaction of water with the Co 3 O 4 (111) surface has not been studied to an extent that would allow a fundamental understanding of its role in the catalytic activity.…”