The universality of like-disperses-like rule for supported simple metal oxide catalysts

The rutile SnO 2 monolayer dispersion capacity on the rutile TiO 2 (r-TiO 2 ) was obviously higher than that on the anatase TiO 2 (a-TiO 2 ) via the qualification of the X-ray diffraction extrapolation method, presenting a like-disperses-like rule. Combined hydrogen temperature-programmed reduction and X-ray photoelectron spectroscopy results revealed that stronger interaction occurred between the supported SnO 2 and the r-TiO 2 than and the a-TiO 2 , thus resulting in higher SnO 2 dispersion on the r-TiO 2 . The SnO 2 /r-TiO 2 catalysts exhibited higher CO activity than the SnO 2 /a-TiO 2 catalysts with the same SnO 2 loadings, verified that the supported SnO 2 and the support sharing a crystalline phase is favorable to achieve the more active dispersed component. The CeO 2 monolayer dispersion capacities on cubic c-ZrO 2 and monoclinic m-ZrO 2 supports further confirmed the universality of the like-disperses-like rule for oxide–oxide systems independent on preparation methods. By comparing a series of oxide–oxide systems, the like-disperses-like rule involved not only the crystalline phase and lattice matching, but also M–O bond characteristics of two oxides. Graphical Abstract