Dynamic Behavior of Pd Species in an LaFe0.95Pd0.05O3 Perovskite

Structural Properties and Catalytic Activity of Sr-Substituted LaFeO3 Perovskite

“…For example, compared with the parent LaFeO 3 , La 1-x Ca x FeO 3 (x = 0.1-0.4) gave almost the same activity [3,15] while LaFe 1-x Mg x O 3 (x = 0.1-0.5) gave much lower activity [20] in CH 4 combustion. We have recently reported that Pd doping of the B site cation in LaFeO 3 perovskite enhanced the catalytic activity and structural stability at high temperatures and in a reducing atmosphere [21,22]. In this work, we extended this to examine the effect of Sr 2+ substitution of the A site cation (La 3+ ) in LaFeO 3 on the structure and catalytic activity in CO oxidation and CH 4 combustion.…”

“…The La 1-x Sr x FeO 3 perovskites (x = 0 or 0.2) were prepared by a sol-gel method described elsewhere [21]. Briefly, 75 ml aqueous solution containing La 3+ , Sr…”

Preparation of LaFe0.95Pd0.05O3 perovskites and their catalytic performances in methane combustion

“…The LaFe 0.95 Pd 0.05 O 3 perovskites were prepared by a solgel process as described elsewhere [17]. Briefly, 75 mL of aqueous solution containing La 3+ , Fe 3+ and Pd 2+ with a molar ratio of 1 : 0.95 : 0.05 was slowly added to 40 mL of EDTA-citric acid-ammonia aqueous solution.…”

“…The consumed lattice oxygen was then replenished by gaseous oxygen through a Mars-Van Krevelen mechanism [26−28]. O 2 -TPD profiles revealed that LFP-1073 sample exhibited enhanced lattice oxygen mobility than LaFeO 3 at temperatures higher than 940 K [17], coinciding with the sequence of their catalytic performances in the same temperature range. Therefore, at temperatures higher than 923 K, the effect of lattice oxygen mobility on the catalytic activity became more prominent and the higher lattice oxygen mobility in LFP-1073 might be responsible for the better activity than in LaFeO 3 .…”

“…We have recently evidenced that the palladium species in a LaFe 0.95 Pd 0.05 O 3 perovskite moved out of the LaFeO 3 lattice under reductive atmosphere with metallic state and reversibly incorporated into the perovskite framework as ionic state under oxidative environment, and the catalytic activity for CO oxidation was closely associated with the chemical state of the Pd species [17]. In the present work, we extended to examine the influence of the calcination temperature on the structural properties of the LaFe 0.95 Pd 0.05 O 3 perovskites and to study their catalytic performances in methane combustion with respect to the activity and stability.…”