Ultra-simple synthetic approach to the fabrication of CeO2–ZrO2 mixed nanoparticles into homogeneous, domain, and core–shell structures in mesoporous spherical morphologies using supercritical alcohols

Abstract

CeO 2 -ZrO 2 composite nanoparticles with mesoporous and spherical morphologies were assembled into different homogeneously dispersed, domain, and core-shell structures by changing the reaction conditions, such as the heating rate, acid, and solvent, in supercritical alcohols. Ce x Zr 1-x O 2 with homogeneous structures were prepared from Ce(NO 3 ) 3 and ZrO(NO 3 ) 2 in the presence of formic acid in methanol by rapid heating (500 °C/min) to 300 °C, while CeO 2 -ZrO 2 with domain structures were obtained by slow heating (5.4 °C/min). Treatment of mesoporous and spherical ZrO 2 nanoparticles with a Ce(NO 3 ) 3 solution in supercritical conditions yielded CeO 2 -ZrO 2 nanocomposites with core-shell morphologies, while solvents playing a key role in controlling the thickness of the outer shell; methanol produced a very thin outer shell structure of cubic CeO 2 and 2-propanol afforded a thick one.

Nickel-Containing Ceria-Zirconia Doped with Ti and Nb. Effect of Support Composition and Preparation Method on Catalytic Activity in Methane Dry Reforming

“…Later, it was proposed to use alcohols instead of water, since the conditions for achieving a supercritical state for them are milder than those for water. Depending on the molecular weight of the alcohol used and branching of the hydrocarbon residue, particles of metal oxides, for instance ceria, with various sizes were obtained [17,18].…”

Catalytic ketonization of palmitic acid over a series of transition metal oxides supported on zirconia oxide-based catalysts

“…24,25 The surface area increment of modied ZrO 2 catalysts is the result of imperfections caused by the added dopant metals to the crystallinity of the catalyst structure hence allowing for more disorder within the catalyst surface, similar to the observations made in previous studies. [26][27][28] It is postulated that high surface area of the metal oxide catalyst leads to higher number of active sites, facilitating a better catalytic activity for ketonization. 29 Besides, the pore volume of modied ZrO 2 catalysts showed slight increment with highest pore volume observed for MnO 2 / ZrO 2 (0.064 cm 3 g À1 ).…”

Porous niobia spheres with large surface area: alcothermal synthesis and controlling of their composition and phase transition behaviour

“…36 As mentioned in the introduction, composite MARIMOs consisting of plural metal oxides have been successfully synthesized. [10][11][12][13] Herein, a one-pot and single-step technique was used to obtain TiO 2 -Nb 2 O 5 composite MARIMOs.…”