Introduction . The spontaneous dispersion of catalytically active species on the support has been widely investigated in heterogeneous catalysis due to interactions between the species and support1 , 2. Highly dispersed or, more strictly, monodispersed active sites endow the supported catalysts with unique catalytic properties. Spontaneous monodispersion can also improve atomic efficiency. Metal oxides with weak internal cohesive energy, e.g., MoO 3 and NiO, can be easily dispe...