METHANE COMBUSTION ON MG-DOPED LACRO3 PEROVSKITE CATALYSTS

A series of terms of the perovskite system LaCr1-xMgxO3 (x = 0 divided by 0.5) were synthesised by the so-called 'citrates method', characte rised and tested for application in the catalytic combustion of methan e. Catalysts have been prepared either in an unsupported or in a MgO-s upported form, obtaining, in this last case, higher catalytic activiti es owing to a better dispersion of the catalytically active species. M g-doping of the basic LaCrO3 perovskite promotes catalytic activity in proportion to Mg/Cr substitution. An Eley-Rideal mechanism (oxygen di ssociative chemisorption on catalytically active sites and reaction wi th methane) could satisfactorily fit the experimental results of a kin etics analysis performed on some supported perovskite catalysts with c omparatively high x values (0.2-0.4).