Influence of the calcination temperature on the structure and reducibility of nanoceria obtained from crystalline Ce(OH)CO3 precursor

Comment on: “Influence of the calcination temperature on the structure and reducibility of nanoceria obtained from crystalline Ce(OH)CO3 precursor,” by Poggio et al., Int J Hydrogen Energy 2011;36:15899–15905

“…The authors say that such a method proved incapable to highlight significant quantitative changes among their spectra, and they explain this as being "probably due to inherent inaccuracy for small degrees of reduction (that is, low amount of Ce 3þ species) and/or lack of linearity for values lower than 35%" [1]. The second method used by the authors involves the peak fitting of Ce3d spectra (a typical example of which they present in Fig.…”

“…The second method used by the authors involves the peak fitting of Ce3d spectra (a typical example of which they present in Fig. 5), and they find that %Ce 3þ spans the range w8% to 2% as a function of calcination temperature [1].…”

“…6), that is, w7.6 (sample C350), and w6.6 (sample C450) [1]. Unfortunately, the authors do not specify the sample to which the peak fitting of Fig.…”

“…5 of Ref. [1]. I Tot Ce xD (x [ 3,4) values designate the sum of the intensities of all Ce 3D -related peaks and of all Ce 4D -related peaks, respectively.…”

“…This arbitrary alteration of the original data affects the validity of neither the comparison between the FWHMs of separate peaks nor their intensity ratios because both the h max values and FWHM values which I measured are scaled by the same factor with respect to those reported in Ref. [1]. Relative errors are always given in parentheses.…”