Oxidative activation of methane on lanthanum oxide and nickel-lanthanum oxide catalysts

In this work, lanthanum oxide (La<inf>2</inf>O<inf>3</inf>) has been studied for the methane partial oxidation reaction. We report long term experimental studies on La<inf>2</inf>O<inf>3</inf>, prepared by the solution combustion method with 5 wt% of Ni being added using chemical reduction method. Thorough characterization is done using XRD, SEM and FTIR. The activity is measured in terms of methane conversion and hydrogen and carbon monoxide selectivity. Methane oxidation is also carried out by varying the residence time, which changes the product distribution. Furthermore, methane activity is studied in the absence of oxygen and effect of pretreatment is also disused in detail. It is observed that the addition of nickel on the La<inf>2</inf>O<inf>3</inf> catalyst (5 % Ni/ La<inf>2</inf>O<inf>3</inf>) increases the catalytic activity significantly. Long term tests at isothermal conditions on both La<inf>2</inf>O<inf>3</inf> and 5 % Ni/La<inf>2</inf>O<inf>3</inf> catalysts are carried out to study the deteriorating effect of carbon (coke) deposition. Hydrogen production with 5 % Ni/ La<inf>2</inf>O<inf>3</inf> is significantly enhanced compared to La<inf>2</inf>O<inf>3</inf>, and it is experimentally observed that both the catalysts show excellent coking resistance capabilities.