Formation and structural characteristics of Pd–Ag/SiO2 and Pd–Cu/SiO2 catalysts synthesized by cogelation

Iron(III) species dispersed in porous silica through sol–gel chemistry

“…In the range of mesopores and macropores, Fe/ SiO 2 -C(M) and Fe/SiO 2 -C(E) exhibit a continuous diameter distribution from a few nm to a few lm and their total porous volumes of 3.3 ± 0.1 and 3.1 ± 0.1 cm 3 /g, see Table 1, are of the order of magnitude of those obtained with aerogels dried under supercritical conditions [7,33]. It has been shown in previous studies that this texture is typical of cogelled catalysts [7,9,34,35]. The bulk densities, q bulk , obtained from mercury pycnometry, confirm the differences observed in the total porous volumes.…”

“…Over the past fifteen years, an attractive method for the preparation of nanometer-sized uniform metal or alloy particles dispersed in the pores of a silica matrix by solgel processing of metal complexes has been developed [6][7][8][9]. This method consists of using alkoxysilane-functionalized ligands of the type (RO) 3 Si-X-L in which the ligand L, is able to form a complex, -L n M m+ , with a metallic cation, M m+ , such as Pd 2+ , Ag + , or Cu 2+ , that is connected to the alkoxide (RO) 3 Si-moiety through an inert and hydrolytically stable tethering organic group, X.…”

Sol- Gel Synthesis of Hematite Nanoparticles and Photo Degradation of Cibacron Red FN-R Dye

“…Among those phases hematite is one of the most attractive and significant metal oxide [5]. Many methods on the synthesis of iron oxide NPs by solgel are developed [6,7]. Tang and his co-workers report the synthesis of α-Fe 2 O 3 nanorods through the calcination of Fe OOH nanorods precursor [8] , Zhang et al [9] use the solgel route to prepare hematite nanoparticles at various temperatures (423 -800 K) .…”

Synthesis of transition metal-doped carbon xerogels by cogelation

“…Such a complexing agent could be incorporated to the growing polymer chains. This process, called 'cogelation', was previously successfully used for the preparation of metal nanoparticles dispersed in 50-100 nm silica particles [17][18][19][20][21]. In these studies, the metal surface remained accessible to gases due to the high micropore volume of silica.…”