Autoreduction of Copper on Silica and Iron‐Functionalized Silica Nanoparticles with Interparticle Mesoporosity

Abstract

Copper‐supported catalysts are of industrial importance in many catalytic processes. Mesoporous silica materials are of particular interest as green heterogeneous catalyst supports. In the present study we demonstrate the nature and reduction properties of copper oxide species, which are influenced by the peculiarity of the silica nanoparticles with interparticle mesoporosity (KIL family) and the presence of a second metal (iron) in the silica matrix. The copper‐containing KIL‐2 and FeKIL‐2 samples are prepared by incipient wetness impregnation. The reduction of copper oxide species is easier on the FeKIL‐2 supported sample in comparison to its KIL‐2 supported analogue, whereas the copper‐containing KIL‐2 sample shows higher catalytic activity in total toluene oxidation. The presence of iron in the FeKIL‐2 structure leads to autoreduction of copper followed by the redispersion and oxidation of metallic copper in the reaction medium; this results in the formation of different types of finely dispersed copper oxide species (<100 nm). The later species possess lower catalytic activity in toluene oxidation in comparison to species that are 100 nm in size and formed on KIL‐2.

Synthesis, characterization, DNA binding, topoisomerase inhibition, and apoptosis induction studies of a novel cobalt(III) complex with a thiosemicarbazone ligand

“…Autoreduction of some copper(II)-containing species is also known to occur as reported in the literature [169][170][171][172][173]. Autoreduction of bischelated copper(II) complexes of 6,6′dialkyl-2,2′-bipyridines [169] and 8-dimethylarsinoquinoline [174] has also been reported.…”

CuO/SBA-15 materials synthesized by solid state grinding: Influence of CuO dispersion and multicycle operation on DeSO performances

“…According to the literature [47], it is possible that such a thermal treatment under nitrogen results in the reduction of the Cu 2+ copper species to Cu + species [58,59] which might be more active for the oxidation-chemisorption of SO 2 . This phenomenon is currently under investigation.…”

Removal of Copper from Aqueous Solutions with Zeolites and Possible Treatment of Exhaust Materials

“…The most active proved to be copper-loaded natural zeolite tuff with higher concentration of copper in starting solution. The activity of calc-CuNaZ-24-150 sample is comparable with the already developed catalysts for the total toluene oxidation [11][12][13][14][15]25]. The additional advantage of calc-CuNaZ-24-150 sample is the application of cheap and available natural zeolite as a support.…”

“…Volatile organic compounds (VOCs) are atmospheric pollutants that contribute to the greenhouse effect, mainly generated from fossil fuel, biofuel and waste incineration installations, petroleum refineries, diesel engines, other industrial productions, and from utilization of organic solvents. [11][12][13][14][15]. Therefore, the development of inexpensive and effective catalysts for VOCs degradation is of great scientific and technological interest.…”