ZnO supported on Al2O3, SiO2, TiO2 and ZrO2 for the Activation of Methane, Ethane and Propane

Arndt S., Uysal B., Otremba T., AKSU Y., Schomaecker R.

14th Nordic Symposium on Catalysis, Marienlyst, Denmark, 29 - 31 August 2010, pp.73, (Full Text)

  • Publication Type: Conference Paper / Full Text
  • City: Marienlyst
  • Country: Denmark
  • Page Numbers: pp.73
  • Akdeniz University Affiliated: Yes

Abstract

The known resources of natural gas are large, therefore there exists a big economical interest in
converting the main components (CH4 as major component, C2H6 and C3H8 as minor components) into
value added products, e.g. olefins [1]. Direct routes to convert these compounds into the desired olefins
are the oxidative coupling of methane and the oxidative dehydrogenation of ethane and propane [1, 2, 3].
1. oxidative coupling of methane (OCM)
CH4 + ½ or 1 O2 → C2H4 or C2H6 + H2O
2. oxidative dehydrogenation of ethane (ODE)
C2H6 + ½ O2 → C2H4 + H2O
3. oxidative dehydrogenation of propane (ODP)
C3H8 + ½ O2 → C3H6 + H2O
However, these processes have still not reached commercial application, due to the lack of suitable
catalysts.
ZnO is considered to be a suitable catalyst. But it has been shown, that it suffers from severe sintering
and deactivation, which starts already below reaction temperature [4]. One possibility to improve the
thermal stability and avoid deactivation is the usage of a support. Most supports influence the catalytic
performance of the supported material, which also has to be considered.
We prepared different loadings of ZnO supported on Al2O3, SiO2, TiO2 and ZrO2. The catalytic
performance for the C-H activation for lower alkanes was investigated for each catalyst. A comparison
of the results allowed an evaluation of the effect of the different support materials on the activity. The
experiments show, that for different reactions the support can increase or even decrease the activity, and
that the results strongly depend on the kind of support used and not on the loading of ZnO.
References
[1] J.H. Lunsford, Catal. Today 63, 165 (2000).
[2] E. Kondratenko and M. Baerns in ''Handbook of Heterogeneous Catalysis'', Wiley-VCH, Chapter
13.17, 3010 (2008).
[3] S.F. Håkonsen and A. Holmen in ''Handbook of Heterogeneous Catalysis'', Wiley-VCH, Chapter
14.11.2, 3384 (2008).
[4] S. Arndt, Y. Aksu, M. Driess and R. Schomäcker, Catal. Lett 131, 258 (2009)