Catalytic destruction of chlorinated C2 compounds on a LaMnO3+δ perovskite catalyst

Abstract

The LaMnO3+δ perovskite shows interesting performances in the total catalytic destruction of chlorinated C2 hydrocarbons selectively to COx (mainly CO2) and HCl. It is shown that the unsaturated molecules are more difficult to destroy than the saturated ones. The saturated chlorinated C2 hydrocarbons are readily converted to their unsaturated equivalent by an unimolecular elimination reaction probably catalysed by Lewis acid sites. The formation of higher chlorinated C2 by-products can be explained by successive chlorination and dehydrochlorination reactions. Addition of water favours the destruction by decreasing the amount of chlorinated by-products and results in an enhanced carbon oxides formation. Oxygen must also be present to prevent the destruction of the active LaMnO3+δ oxygen overstoichiometric structure.