Methane activation by NO2 on Co loaded SBA-15 catalysts: The effect of mesopores (length, diameter) on the catalytic activity

In a general model of “three-function deNO_x” catalyst, the partial oxidation of methane by NO₂ is an important step (CH₄ + NO₂ → C_xH_yO_z + NO). To study the effect of the length and diameter, in the mesopores of SBA-15, we have synthesized catalysts with 3 wt.% cobalt supported on SBA-15, with differences in length and diameter of channels. Three different cobalt species were detected on all catalysts. We demonstrated by TPSR experiments that the activity of cobalt/SBA-15 catalysts is affected by the length, the diameter and connections between mesopores of the SBA-15 supports. We show that by changing textural properties of silica support the temperature of 100% conversion of NO₂ into NO can decrease by more than 100 °C.