fulltext.study @t Gmail

Insights on the role of Ru substitution in the properties of LaCoO3-based oxides as catalysts precursors for the oxidative reforming of diesel fuel

Paper ID Volume ID Publish Year Pages File Format Full-Text
46705 46445 2012 10 PDF Available
Title
Insights on the role of Ru substitution in the properties of LaCoO3-based oxides as catalysts precursors for the oxidative reforming of diesel fuel
Abstract

The partial substitution of Co by Ru in lanthanum cobaltite perovskites (LaCo1−xRuxO3, x = 0.05 and 0.2) and its influence on the reducibility and structural modifications in the perovskite lattice have been evaluated by N2 adsorption isotherms, in situ X-ray diffraction (XRD), temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). Characterization of LaCo1−xRuxO3 perovskite precursors reveals that Ru is incorporated into the perovskite lattice, producing a distortion of the original rhombohedral structure, a decrease in mean crystallite size and some increase in the surface area. The structural evolution of the LaCo1−xRuxO3 precursors under a reductive treatment indicates that Ru promotes the reducibility of the perovskite leading to a greater reduction degree of cobalt species. Moreover, the smaller perovskite crystallites obtained with the partial substitution of cobalt by ruthenium evolve to smaller crystal domains of both Co0 and La2O3 after reduction. The catalysts formed after the reduction of perovskite precursors present very high catalytic efficiency to extract hydrogen from diesel molecules by oxidative reforming. However, those catalysts derived from Ru-substituted perovskites show better catalytic performance associated with the higher development of active metallic phases achieved on the surface of these catalysts. Additionally, Ru promotes the catalytic activity and stability for this reaction increasing the reduction degree of cobalt and decreasing coke formation and sulfur poisoning through the formation of smaller cobalt crystallites.

Graphical abstractCatalysts derived from Ru-substituted perovskites (LaCo1−xRuxO3, x = 0.05 and 0.2) show better catalytic performance associated to the higher development of active metallic phases achieved on the surface. Additionally, Ru promotes the catalytic activity and stability for this reaction increasing the reduction degree of cobalt and decreasing coke formation and sulfur poisoning through the formation of smaller cobalt crystallites.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlight► Co and Ru-Co lanthanum perovskites as catalysts precursors. ► Catalysts for hydrogen production by oxidative reforming of diesel. ► We found Ru as a promoter. ► Ru incorporation decreases coke formation and sulfur poisoning.

Keywords
Hydrogen; Diesel; Oxidative reforming; Lanthanum cobaltite; Ruthenium
First Page Preview
Insights on the role of Ru substitution in the properties of LaCoO3-based oxides as catalysts precursors for the oxidative reforming of diesel fuel
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volumes 113–114, 22 February 2012, Pages 271–280
Authors
, , , , , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis