Mechanochemical redox: a calcination-free process to support CoMnOx catalysts†
An interesting approach (mechanochemical redox-based loading method, MRL) was introduced to support cobalt manganese oxides on TiO2, SiO2 and Al2O3. Compared with traditional loading methods (co-precipitation and impregnation), MRL showed better performance in catalyst preparation (solvent- and calcination-free syntheses), specific surface area of the catalyst (84 m2 g−1 by MRL, which is much higher than 39–44 m2 g−1 by co-precipitation and impregnation methods) and dispersion of active species. In the oxidation reaction of CO, supported CoMnOx by MRL exhibited good activity (T100 = 175 °C) and favorable stability (T = 160 °C, 100 h), better than the control samples (T100 = 280 °C by impregnation and T100 = 375 °C by co-precipitation). The breakage action, friction heating and instant high pressure by ball milling could contribute to the generation of interstitial porosity, better dispersion of CoMnOx and the generation of more active sites. Thus, MRL seems like a potential alternative to the synthesis of supported catalysts.