Hydrothermal Synthesis of Rare-Earth Oxide Nanocatalysts for Automotive Exhaust Clean-Up

Abstract

Three rare-earth metal oxide nanopowders (CeO2, PrO2, and TbO2) were synthesized using a facile hydrothermal method in a Teflon-lined autoclave. The rare-earth metal oxide nanocrystals with variable morphology were prepared by controlling the synthesis conditions with temperatures in the range of 70−220 °C. X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and temperature programmed reduction (TPR) were used to characterize the average structures and redox properties of these materials. Transmission electron microscopy (TEM) was used to investigate the morphology, particle size, and formation and growth mechanisms of the rare-earth metal oxide nanoparticles in solution-based environment.

Formation of self-assembled Gd2O3nanowire-like structures during epitaxial growth on Si(001)

“…This would be an indication for the growth of the cubic structure with (110) orientation with two orthogonal domains, as already reported for Gd 2 O 3 layers grown at a lower temperature. 19 Further verication of this fact is the identical RHEED pattern in the 90 rotated [1][2][3][4][5][6][7][8][9][10] direction of the substrate (not shown). Furthermore, the inuence of a 4 miscut substrate on the growth of the Gd 2 O 3 layer was also investigated.…”

“…Rare earth oxides (REOs) gained lots of attention during the past years due to their broad field of applications, 1 such as catalysts in the automotive industry, 2 as additives in the glass industry, 3 in ceramics 4 and additives in batteries. 5 They can be also used in high-energy solid-state laser systems and scintillators.…”

Overview: Modification of Cerium Oxide in Three-Way Catalysts

“…Hence, the introductions of small amount of metal oxides to be a powerful additional tool in the design of innovative catalytic materials with the enhancement of catalytic activity at lower temperature [14]. It has been reported that the addition of metal oxides such as transition metals [3,5,[15][16][17][18], rare earth metals [19][20][21][22][23][24][25], and alkaline earth metals [26][27][28] is able to enhance the thermal stability and oxygen storage capacity value. Materials Engineering and Automatic Control III…”

Interfacial layer formation during the growth of Gd2O3 on Si(001) and its thermal stability

“…Rare earth oxides (REOs) attracted lots of attention during the last decades due to their wide field of applications [1]. They are used as catalysts in the automotive industry [2], as additives in the glass industry and batteries [3,4] and ceramics [5]. They can be also used in scintillators and high-energy solid-state laser systems [6,7].…”