Deceleration of SO2 poisoning on PtPd/Al2O3 catalyst during complete methane oxidation
Artikel i vetenskaplig tidskrift, 2018

The inhibiting effect of SO2 on the catalytic activity of the monometallic Pt/Al2O3 and Pd/Al2O3, as well as on bimetallic PtPd/Al2O3 catalyst for the complete oxidation of methane under lean conditions has been studied. Flow reactor experiments, in-situ DRIFT spectroscopy and characterization with XPS, STEM-EDX were performed. It was found that the addition of Pt to the Pd/Al2O3 resulted in a catalyst that was more robust towards sulfur poisoning. XPS results revealed residual sulfates on catalyst surface after regeneration. This was confirmed with EDX analysis, which demonstrated that sulfur was accumulated in noble metal particles and especially in the region of the particle rich in Pt. Although the catalyst has been deactivated in the presence of both SO2 and H2O, an additional presence of NO in the gas mixture of reactants resulted in an increased lifetime of the sample under reaction conditions. This NO effect strongly depends on the temperature of experiments and is most intense at a temperature close to 550 degrees C A postponed inhibition caused by the addition of NO may be explained by the DRIFTS results, which demonstrated that the presence of NO lowers the sulfate formation and mostly surface sulfites are observed that increase the lifetime of the catalyst during SO2 exposure.

Inhibition

Methane oxidation

Promotion

Sulfur poisoning

Noble metal

Författare

Nadezda Sadokhina

Chalmers, Kemi och kemiteknik, Kemiteknik, Kemisk apparatteknik

Gudmund Smedler

Johnson Matthey AB

Ulf Nylen

Scania CV AB

Marcus Olofsson

AVL MTC Motortestcenter

Louise Olsson

Chalmers, Kemi och kemiteknik, Kemiteknik

Applied Catalysis B: Environmental

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

Vol. 236 384-395

Metandrivna motorer för tunga fordon med låg bränsleförbrukning och Euro VI emissioner

Energimyndigheten, 2015-12-01 -- 2017-12-31.

Energimyndigheten, 2013-04-01 -- 2015-10-01.

Ämneskategorier

Kemiska processer

Annan kemiteknik

Annan kemi

DOI

10.1016/j.apcatb.2018.05.018

Mer information

Senast uppdaterat

2018-09-28