Comment on "Non-pitch coal-based activated coke introduced CeOx and/or MnOx for low temperature selective catalytic reduction of NOx by NH3" by Fu et al., RSC Adv., 2016, 6, 8539-8548

In the present letter I discuss the XPS analysis the authors conducted on a non-pitch, coal-based, activated coke catalyst, and which they interpreted as showing that addition of MnO-CeO-b oxides (with loading, b, in the range 0.50 to 7.40) enhances the catalyst's de-nitrification performance through a MnO-assisted oxidation of the cerium to the Ce ion. On the basis of a careful assessment of Ce3d and Mn2p spectra I argue that such an interpretation is unwarranted. I propose that it is the total number of oxide sites (MnO and CeO) added to the catalyst that enhances its de-nitrification powers.