Oxidative coupling using alkali-promoted

Alkali-Metal-Promoted Metal Oxides. Researchers at Texas A M University studied methane oxidative coupling using MgO promoted with Oxygen cofeeding was used in all... 

Additives can strongly influence the coupling. Foreign anions should be excluded, because they disturb the necessary formation of a carboxylate film at the anode. Their unfavorable effect increases with the charge of the anion. Foreign cations that can form oxide layers or promote radical oxidation (Fe ", Co +, Cu +, Mn +) lower the coupling yield. Alkali and alkylammonium ions have no negative effect. Methanol is the solvent of choice, but acetonitrile can also be used if some water is added. 

The Institute of Gas Technology recently patented a boron/alkali metal- promoted, metal oxide catalyst for oxidative coupling of methane. The catalytic studies were performed between 700 and 820 °C. The best activity (21%) and selectivity (86%) were achieved using 1% Li/0.2% B promoted on MgO. 

This section reports a series of examples of application of the cluster model approach to problems in chemisorption and catalysis. The first examples concern rather simple surface science systems such as the interaction of CO on metallic and bimetallic surfaces. The mechanism of H2 dissociation on bimetallic PdCu catalysts is discussed to illustrate the cluster model approach to a simple catalytic system. Next, we show how the cluster model can be used to gain insight into the understanding of promotion in catalysis using the activation of CO2 promoted by alkali metals as a key example. The oxidation of methanol to formaldehyde and the catalytic coupling of prop)me to benzene on copper surfaces constitute examples of more complex catalytic reactions. 

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