Methane activation on oxyhalogenated rare-earth systems: Effect of Pr3+ substitution in LaOCl host structure on CO2 formation

Catalytic activity of LnOX (Ln = Sm, La or Nd; X = Cl or Br) and Ln(1-x)Lm( x)OX (Ln = La and Lm = Pr, 0 less than or equal to x less than or equal to1 ) catalysts has been studied using a continuous flow reactor system. Methan e oxidation using LnOX results in an increase of CO2 selectivity in the ord er Nd > La > Pr > Sm, while using Ln(1-x)Lm(x)OX systems CO2 selectivity is enhanced by increasing partial lanthanum substitution with praseodymium. A decrease in CO and Ct hydrocarbons selectivities is also observed at isoco nversion. The different compounds structures studied do not change with tim e under reaction conditions within the temperature range at which the catal ysts are stable.