3D hierarchically structured Ce1-xGdxO2-x/2 mixed oxide particles: the role of microstructure, porosity and multi-level architecture stability in soot and propane oxidation.

In this paper, synoptic description of the hierarchical architecture of mixed ceria particles and its function in catalytic propane and soot oxidation has been presented. The influence of temperature and dopant concentration on the micro-to macroscale structure of the star-shaped particles has been thoroughly investigated by various physicochemical techniques. Two temperature-dependent growth modes of ceria nanoparticles has been observed and their dopant-dependent influence on mesocrystal architecture have been described. It appeared that presence of dopant changes the pattern of nanoparticles intergrowth which ultimately introduces additional porosity into 3D hierarchically structured material (r(av )=19 nm). Furthermore, emergent phenomenon in catalytic propane oxidation was observed. The substantial increase of propane conversion via low-temperature surface oxidation mechanism was ascribed to nanocrystallites mesoscale organization forming porous hierarchical material. No such conversion was present for a comparative sample of non-organized ceria nanoparticles. Also, increased stability of such architecture was demonstrated in soot combustion tests.

Automated summary

This paper presents a synoptic description of the hierarchical architecture of mixed ceria particles and its function in catalytic reactions. The influence of temperature and dopant concentration on the structure of the particles was thoroughly investigated. The study observed two temperature-dependent growth modes of ceria nanoparticles and described their dopant-dependent influence on the mesocrystal architecture. It was found that the presence of dopant changes the pattern of nanoparticles intergrowth and introduces additional porosity into the material. The hierarchical structure also exhibited improved catalytic performance and stability in propane and soot oxidation.