Mechanochemical activation of industrial catalysts: 1. Catalytic properties of STK, NTK-10-1, and nickel-chromia catalysts and their mechanical mixtures in redox reactions involving nitrogen oxide, carbon monoxide, and hydrocarbons

The effect of mechanochemical activation on the activity of mechanical mixt ures of the industrial catalysts STK and NTK-10-1 and a nickel-chromia cata lyst as binary compositions in the reactions of selective reduction of nitr ogen oxides with propane in the presence of oxygen and severe oxidation of hydrocarbons (using toluene as an example), as well as the activity of the mechanochemical catalyst SNM-1, which is similar to the industrial catalyst in composition, in the reaction of deep oxidation of CO were examined. It was shown that the activity of catalytic compositions prepared by joint gri nding of components in a planetary activator in the reaction of selective r eduction of nitrogen oxides with propane substantially depended on the cond itions of mechanochemical treatment (grinding body load and grinding time). At the optimum load on the materials of the system (load 1 : 5, grinding t ime 10 min), the activity of the catalytic compositions obtained from the c atalysts NTK-10-1 and Ni-Cr oxide by the mechanochemical procedure was note d to increase as manifested by shifting the NO conversion temperature maxim um to lower temperatures by 100 degrees C. It was found that the catalytic activity of mechanical mixtures and mechanochemical systems (regardless of their preparation conditions) in the reaction of deep oxidation of toluene is higher than that of the individual catalysts composing the formulations. The catalyst prepared from corresponding oxides by the mechanochemical pro cedure to have the same composition as the industrial catalyst SNM-1 obtain ed by the traditional coprecipitation method exhibits approximately the sam e activity as the latter in CO oxidation reaction. In the view of high envi ronmental safety of the technology of catalyst preparation by the mechanoch emical method, opportunities for the synthesis of catalysts of various comp ositions with properties superior to those of analogous industrial catalyst s prepared by the conventional procedures and for rapid launching of produc tion of catalysts of any prescribed composition, this method was shown to h old much promise.