Hydrocarbons, oxidation, catalysis surface effects

Perovskite oxides are effective catalysts for various reactions, such as CO oxidation,total and partial oxidation of hydrocarbons, NOx decomposition, hydrogenation, " hydrogenolysis, and photocatalysis. Two types of catalytic processes are proposed for the catalysis of perovskites, namely, suprafacial and intrafacial catalysis." During suprafacial catalysis, the reactions between adsorbed species on the surface are much faster than reactions involving lattice oxygen, as in low-temperature oxidation of CO. In this case, the reaction rate appears to be correlated... 

Stable nano/mesoporous materials with mixed oxides such as zeolites, clays, and other minerals are widely used in various fields catalysis, adsorption, ion-exchange, separation, etc. because of their catalytic activity in acid/base and redox (e.g., materials with titania phase) reactions, ability to sorb selective molecules of diverse types, participate in ion-exchange reactions, providing sieve effects, etc. (Tanabe 1970, Grandjean and Laszld 1989, Rocha and Anderson 2000, Cundy and Cox 2005, Tao et al. 2006). The most important processes that utilize the selective properties of these materials are alkylation and isomerization of aromatic hydrocarbons as well as conversion of methanol to hydrocarbons, and some other reactions. Silicalite is an extreme type of the materials with the ZSM-5 zeolite structure but whose aluminum content is negligible. Therefore, unlike conventional zeolites, silicalite does not possess ion-exchange properties, and its surface has a weak affinity to water. 

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