LaCo1−x Pd x O3 Perovskite-Type Oxides: Synthesis, Characterization and Simultaneous Removal of NO x and Diesel Soot

Abstract

A series of naometric perovskite catalysts LaCo 1-x Pd x O 3 (x = 0, 0.01, 0.03) were prepared via a solution combustion synthesis route using metal nitrates as oxidizers and urea as fuel. It is essential to add a certain amount of ammonia aqueous solution to Pd 2? ions solution in the catalyst preparation process. Homogeneous nanoparticles LaCo 1-x Pd x O 3 catalysts with the sizes in the range of 68-122 nm were obtained and characterized by using of XRD, BET, H 2 -TPR, XPS, SEM and TEM. Pd was successfully introduced into the LaCoO 3 perovskite lattices. Further information was obtained by using XPS upon the LaCo 0.97 Pd 0.03 O 3 (with NH 4 OH) sample after H 2 -TPR. The results revealed that surface Pd was reduced to the metallic state at the end of the first step in the H 2 -TPR experiment, and some surface Co could be reduced to metallic Co simultaneously. The catalytic properties were investigated for simultaneous NO x -soot removal reaction. The performance of LaCo 1-x Pd x O 3 catalysts were greatly improved by the partial substitution of Pd. The maximum NO conversion into N 2 and the ignition temperature of soot are 32.8% and 265°C, respectively.

Catalytic Oxidation of Soot on a Novel Active Ca-Co Dually-Doped Lanthanum Tin Pyrochlore Oxide

“…It can be noticed that in the case of LCSC, quite low signal intensity is present in the spectra, indicating that Ca ions distort the surroundings around Co ions in crystal. Nevertheless, the prominent peak of 2p 3/2 over two samples powerfully proves that Co is in +3 valance state, as reported in previous data [28,31]. …”

“…Both La 3d 3/2 and La 3d 5/2 show double peaks. Natile et al [28] once explained that the bimodal was resulted from the energy loss phenomenon (“jitter” satellite) caused by the charge transfer of O 2p → La 4f or the strong final state mixing of electronic configuration. The substitution of La by Ca atoms caused a small shift in these peaks to higher binding energies, which was probably connected with a different chemical environment.…”

Synthesis of cube-like Ag/AgCl plasmonic photocatalyst with enhanced visible light photocatalytic activity

“…The resultant product was washed with deionized water and collected by centrifugation. The Cl − concentration in the raw hot spring is 1131.1 mg/L, which has been reported in our previous literature [17]. The Cl − Catalysis Communications 59 (2015) 151-155 concentration used in this work is about 141.4 mg/L by diluting the raw hot spring.…”

Diesel soot combustion catalysts: review of active phases

“…Lithium introduction on chromium position of LaCrO 3 soot combustion perovskite catalysts has shown to improve the activity due to the enhancement of the amount of weakly chemisorbed oxygen O − species (Fino et al, 2006b). The simultaneous introduction of potassium on lanthanum position and copper on manganese position of the LaMnO 3 perovskite also enhanced the catalytic behavior (Peng et al, 2007), and also the partial substitution of lanthanum by alkali metal cations (Wang et al, 2008;Russo et al, 2008b) and cobalt by palladium (Yao 2009) on LaCoO 3 .…”