direkt zum Inhalt springen

direkt zum Hauptnavigationsmenü

Sie sind hier

TU Berlin

Page Content

New Catalysts for the C-H Activation of lower Alkanes

Lupe

The C-H activation in saturated alkanes is the crucial step for their functionalisation and combustion. Among the light alkanes methane is the most stable compound and therefore the most diffcult molecule to activate. The activation of ethane and propane is less demanding and therefore lower reaction temperatures are possible.

The conversion of methane into value added products is of high interest for the chemical industry, as methane is the major constituent of natural gas, whose reserves are expected to be much higher than those of crude oil. Furthermore using natural gas has a much lower environmental impact than the usage of oil. Ethane and propane are also available in large amounts from natural gas and other sources.
Currently these gases are mostly used for the production of energy and heat. Their usage as a carbon source for the chemical industry is limited, as no process has yet been fully developed.
In principle there are two ways of converting them, especially methane, into value added products. In the indirect way, they are converted into synthesis gas and then being processed via Fischer Tropsch (FT). This process is well known, but very energy consumptive. An alternative route is the direct way, therein the synthesis gas step is evaded and the gases are directly converted into the desired products, like the oxidative coupling of methane (OCM), in which methane is coupled to ethane and/or ethene (The Figure shows the reaction network of the oxidative coupling of methane). As methane is so diffcult to activate, the OCM reaction is performed at high temperatures, where many catalysts su er from severe stability and selectivity problems.
The reactions for the conversion of methane, ethane and propane to the corresponding ole ns are:

  1. Oxidative Coupling of Methane:
    2 CH4 + O2 → C2H4 oder C2H6 + H2O
  2. Oxidative Dehydrogenation of Ethane:
    C2H6 + ½ O2 → C2H4 + H2O
  3. Oxidative Dehydrogenation of Propane:
    C3H8 + ½ O2 → C3H6 + H2O

The structures of methane, ethane and propane are similar. Due to the structural similarity, one catalyst should be able catalyse the C-H activation and therefore the reaction 1-3, for these three molecules. However, the energy required for the activation of a C-H bond is di erent for each reaction, consequently the ODP, ODE and OCM reactions run at very di fferent temperatures. Therefore catalytic testing over a broad temperature range is necessary and possible.
In cooperation with di erent research groups, new catalytic materials are synthesized and their catalytic performance and the kinetic are investigated. Through the interplay between the synthetic, analytic and catalytic testing groups, we are trying to improve the understanding of the di fferent reactions. This should enable us to develop and synthesize more active and selective catalysts.
In addition we investigate the conversion of the product stream of the OCM reaction to more easily separable and more valuable products.
Our research group is equipped with all facilities necessary for high throughput screening, detailed catalytic testing and determining reaction kinetics.

Zusatzinformationen / Extras

Quick Access:

Schnellnavigation zur Seite über Nummerneingabe

Auxiliary Functions

This site uses Matomo for anonymized webanalysis. Visit Data Privacy for more information and opt-out options.