Influence of the synthesis method on structural properties and catalytic activity for oxidation of CO and C3H6 of pirochromite MgCr2O4

Synthesis of nanostructured pirochromite magnesium chromate with egg shell membrane template

“…The calculated values of average crystallite size (t) were found to be 30.8 and 63.2 nm for the 800 and 1000°C annealed samples, respectively, these values are listed in Table 1. In comparison, these values are within range of the reported values of 28.7 nm for particles prepared by conventional solid phase reaction (Khalaf et al 2016), 30.2 nm by sol-gel method (He 2010) and 52.4 and 6.4 nm by sol-gel and co-precipitation with reverse microemulsion (Rida et al 2010). Figure 6band c is a presentation of the powder X-ray diffraction profiles for the annealed boiled ESM templated MgCr 2 O 4 nanocrystalline powders.…”

“…The development of a synthesis route capable of producing MgCr 2 O 4 nanomaterials with controlled size and morphology is important due to their potential applications as smart and functional materials. Various methods, such as solid state reaction (Finocchio et al 1995), sol-gel method (SG) (Andrade et al 2006), co-precipitation (Zhang et al 1987), solution combustion (Arai et al 1986), co-precipitation within reverse micro-emulsion (Rida et al 2010), combustion method (Hosterman et al 2013) and conventional double sintering ceramic technique (Khalaf et al 2016) have been applied in the preparation of pirochromite based nanoparticles. Nevertheless, some of these methods are generally complicated, non-reliable, timeconsuming, and expensive for large scale production.…”

Mössbauer studies of spinellides of Mg(FeXCr2-X)O4 system obtained by the hydroxide co-precipitation method

“…Ions Mg 2+ and Fe 3+ can take both tetrahedral and octahedral position, therefore, the MgFe 2 O 4 spinel has a mixed type of cation distribution in sublattices [23,24]. The studied magnesium ferrite-chromite system Mg(Fe x Cr 2-x )O 4 can be written as 4 where ε is the Me 3+ fraction in the tetrahedral sublattice, x is the number of Fe ions in the sample (0£x£2) and the cations located in the octahedral sublattice are taken in square brackets.…”

“…Spectra of samples with х=0. 25 4 (0≤x≤1) samples produced by the ceramic technology were carried out in [18], and samples of Fe 1-x Mg x Cr 2 O 4 were studied in [19].…”

“…The wide range of properties determine their use in production of electrodes [1][2][3], as catalysts [4,5], adsorbents [6] of materials with high resistance and low losses in the long-wave part of SHF range [7], etc.…”