Theoretical Approach to the CH4 Decomposition on BaTiO3(001)

Oxide configurations with perovskite structures exhibit some interesting and controllable properties. BaTiO₃ compounds have attracted considerable attention due to their potential use as electric and optical applications (1). Additionally, BaTiO₃ has been studied for its catalytic properties in the oxidative coupling of methane (2), partial oxidation of methane (3) and for the total oxidation of methane (4) showing some promising results. Moreover, the presence of BaTiO₃ on the anode material showed to suppress the C deposition for the low temperature dry methane reforming (5). In a similar way, BaTiO₃ has been used as anode for solid oxide fuel cells (SOFCs) exhibiting quite low performance when methane was employed as fuel, but its performance increased in the presence of sulfur containing fuel (6). Although, this material showed some curious properties when used partially or totally as anode for SOFCs to date there are only speculations regarding its potential. In several occasions theoretical studies have been used to elucidate the phenomena behind some exciting properties such as catalytic behaviour. However, this is not any easy task since heterogeneous catalytic processes are complex to model due to the absence of information on the molecule-surface interaction, and the effect that the operating conditions and catalyst preparation have on its performance. In this work an idealized model will be used to describe the methane decomposition on the surfaces of BaTiO₃(001) employing density functional theory (DFT) method. Preliminary results show that the TiO₂-terminated surface is approximately four times more active for the total decomposition of methane than the BaO-terminated surface.

References

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