Stabilization of alumina by addition of lanthanum

Dopants adsorbed as single atoms prevent degradation of catalysts

“…Stabilization of γ-Al 2 O 3 by La is often suggested to be due to LaAlO 3 or La 2 O 3 monolayers on the surface, and the debate about the formation of one phase over another is still ongoing 10,11,12,13,14,15 . We explored the possibility of clustering of surface La atoms.…”

Improvement of Silica–alumina Supports for Diesel Oxidation Catalysts through Control of Both Composition and Pore Structure

“…The activity of the SiO2-containing catalyst for NO oxidation was slightly decreased by aging, whereas the HC oxidation activity was actually improved and showed higher activity than the Al2O3-only catalyst. This result is not unexpected, since it has been demonstrated that the thermal stability of Al2O3 is increased by SiO2 doping 6), 7) . Thus we concluded that SiO2 represents a promising secondary component for the Al2O3 support in a DOC.…”

“…To date, extensive research has been carried out to improve DOC support materials with regard to their compositions and pore structures. In terms of the composition, the addition of secondary components such as Fe 3) , Mn 4) , W 5) , and Si 6), 7) to Al2O3 has been investigated as a means of improving thermal durability and controlling the acidity/basicity balance. With regard to pore structure, multidimensional-structured Al2O3 materials possessing pores of different size scales, such as micro-meso macro 12) , have been studied worldwide in recent years with the expectation that larger pores play a role in the formation of gas diffusion channels and smaller pores act to distribute the active catalytic component 13) .…”

Preparation and characterization of monolithic Al₂O₃–SiO₂ aerogel

“…The addition of silica is effective in suppressing the phase transformation and maintaining the porous structure after heat treatment. 7),16), 17) The average pore size and pore volume of the as-prepared samples are provided in Table 2. With the increase of silicon content, average pore size firstly increase and then decrease, also the pore volume and specific surface area exist a directly proportional relationship.…”