Complete methane oxidation over Ba modified Pd/Al2O3: The effect of water vapor
Artikel i vetenskaplig tidskrift, 2018

The effect on complete methane (CH 4 ) oxidation activity by an addition of up to 2 wt.% barium (Ba) promoter to alumina supported palladium (Pd/Al 2 O 3 , 2 wt.% Pd) was investigated. The catalyst samples were characterized with various techniques; temperature programmed oxidation (TPO), temperature programmed reduction with CH 4 (CH 4 -TPR), X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM) and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS). Flow reactor was used to investigate the CH 4 oxidation activity in the presence and in the absence of water vapor and also to evaluate the possibility to regenerate the catalytic activity after water vapor exposure. The results from the TPO and the CH 4 -TPR experiments together with the XPS analysis gave no evidences for electronic promotion of the catalytic activity by addition of 0.5–2 wt.% Ba. This goes in line with the CH 4 conversion in dry gas condition, which was not affected by the Ba addition. However, we observed that an addition of Ba to Pd/Al 2 O 3 enhances the CH 4 oxidation activity in the presence of water vapor, hence mitigates the effect of water deactivation. Interestingly, it was also seen that after water vapor exposure, the CH 4 oxidation activity could be regenerated to greater extent for the Ba promoted samples, particularly for the regeneration temperatures of 500–600 °C. Our results clearly show that the support influences the water deactivation of the active palladium sites and that the addition of barium is beneficial for the catalyst regeneration.

Pd

Methane oxidation

Regeneration

Water deactivation

Ba

Författare

Ida Friberg

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk reaktionsteknik

Kompetenscentrum katalys (KCK)

Nadezda Sadokhina

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk apparatteknik

Kompetenscentrum katalys (KCK)

Louise Olsson

Kompetenscentrum katalys (KCK)

Chalmers, Kemi och kemiteknik, Kemiteknik

Applied Catalysis B: Environmental

0926-3373 (ISSN) 1873-3883 (eISSN)

Vol. 231 242-250

Ämneskategorier

Annan kemiteknik

Annan kemi

Organisk kemi

DOI

10.1016/j.apcatb.2018.03.003