Studies on the SbOx species of SbOx/SiO2 catalysts for methane-selective oxidation to formaldehyde

Effect of Cu and Sb active sites on the acid–base properties and reactivity of hydrated alumina for glycerol conversion by dehydrogenation and dehydration reactions

“…† Commercial Sb 2 O 3 (bulk) gives a relatively broad charge transfer band in the 200-300 nm wavelength range (6.21-4.16 eV) with a small shoulder at 359 nm. The profile spectra of the commercial sample show the presence of majority of antimony oxide species that are assigned to the aggregated Sb 3+ and Sb 4+ (245 and 277 nm) with a small fraction of Sb 5+ (359 nm), 16,46 in agreement with the results of XRD (Fig. 1b).…”

“…The Sb/Al sample prepared by wet impregnation of antimony on the Al sample shows an intense absorption band with a maximum at 200 nm that extends above 400 nm, corresponding to ligand-to-metal charge transfer transition (LMTC) of the O 2− → Sb 3+ . 46,47 However, depending on the antimony loadings, different SbOx species may be present on the surface of the supported sample (Sb/Al), such as Sb 2 O 4 . Thus, the displacement of the absorption band to lower wavelengths and an increase in the signal intensity observed for the Sb/Al catalyst should be due to the isolated tetrahedral coordinated Sb 3+ oxide species well dispersed on the support.…”

A novel Ce–Sb binary oxide catalyst for the selective catalytic reduction of NOx with NH3

“…The typical peaks assigned to α-Sb 2 O 4 (ref. 27) and CeO 2 (ref. 16 and 28) were observed over SbO x and CeO x catalysts, respectively.…”

“…7, over the SbO x catalyst two reduction peaks centering at about 613 and 699 °C can be observed, which can be assigned to the reduction of Sb 5+ to Sb 3+ and Sb 3+ to Sb 0 , respectively. 27,39 Considering the low intensities of H 2 -TPR profiles over Sb1Cex catalysts above 650 °C and over CeO x , these signals are magnified 10 times. CeO x exhibited two reduction peaks at around 470 and 780 °C.…”

Thermoelectric Properties of Silver Antimonate with Mixed Valency of Antimony

“…The Sb 3d 3/2 XPS spectra of NS and NAT-NS are shown in Figure 3(b) and Figure 3(c), respectively. As for the oxidation states of Sb, the peaks at 540.7 and 539.7 eV are assigned to the 3d 3/2 orbital of Sb 5+ and Sb 3+ , respectively [13]. To quantitatively evaluate the Sb 3+ /Sb 5+ atomic ratios, peak deconvolution was performed using a Gaussian lineshape.…”