Alkali hydroxides as promoters of Mn3O4 in the selective reduction of 
nitrobenzene; an X-ray photoelectron spectroscopy, ultraviolet photoelectron 
spectroscopy and ion scattering spectroscopy study

Maltha, A.; Muhler, Martin; Ponec, V.

doi:10.1016/0926-860X(94)80379-X

Item

ITEM ACTIONSEXPORT

Add to Basket

Local TagsRelease HistoryDetailsSummary

Released

Journal Article

Alkali hydroxides as promoters of Mn₃O₄ in the selective reduction of nitrobenzene; an X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy and ion scattering spectroscopy study

MPS-Authors

/persons/resource/persons21898

Muhler, Martin
Physical Chemistry, Fritz Haber Institute, Max Planck Society;

External Resource

No external resources are shared

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

Fulltext (public)

There are no public fulltexts stored in PuRe

Supplementary Material (public)

There is no public supplementary material available

Citation

Maltha, A., Muhler, M., & Ponec, V. (1994). Alkali hydroxides as promoters of Mn₃O₄ in the selective reduction of nitrobenzene; an X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy and ion scattering spectroscopy study. Applied Catalysis A: General, 115(1), 69-84. doi:10.1016/0926-860X(94)80379-X.

Cite as: https://hdl.handle.net/21.11116/0000-0009-A283-B

Abstract

The promoting mechanism of alkali ions on Mn₃O₄ in the selective reduction of nitrobenzene has been investigated using X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy and ion scattering spectroscopy. It appeared that the alkali ions accumulate on the outermost surface layer, but do not change the oxidation state of manganese. Heating of the fresh catalysts in ultra-high vacuum results in a disappearance of the alkali ions from the surface. This shows that the alkali ions migrate easily over the surface at elevated temperatures. However, when the catalysts have been treated with nitrobenzene, the same heating procedure does not result in a disappearance of the promoter ions. Moreover, it can be seen that the surface has been covered with adsorbates derived from nitrobenzene. It can be concluded that the promoting effect is not due to the electronic structure changes in the interior of the Mn₃O₄ catalyst, but is rather due to one of the following mechanisms: (a) an electrostatic field effect of alkali cations or (b) the formation of intermediates with the reaction components, in the adsorbed layer.