Coke Minimization in Dry Reforming of Methane by Ni Based Mesoporous Alumina Catalysts Synthesized Following Different Routes: Effects of W and Mg

Abstract

Ni based mesoporous alumina (MA) catalysts were synthesized by sol–gel (SGA) and hydrothermal (MA) methods, following impregnation and one-pot synthesis routes and catalytic performances of these materials were tested in dry reforming of methane. Results proved the importance of synthesis procedure of the MA supports on the activity and coke resistance of the synthesized materials, containing 16 % Ni. Among these catalysts, MA prepared by the sol–gel technique (Ni@SGA) showed the highest activity in dry reforming reaction. However, largest coke formation was observed with this catalyst. Although the activity of the catalyst prepared by the impregnation of Ni into MA, which was prepared by the hydrothermal route (Ni@MA), was somewhat lower than the activity of Ni@SGA, almost no coke formation was observed during a reaction period of 4 h at 600 °C with this catalyst. Catalytic performance of this material was also highly stable. Impregnation of 9 % W into Ni@SGA considerably improved the coke resistance of the catalyst. However, modification of Ni@SGA by Mg was not as effective. Results proved that almost zero coke formation was achieved by impregnation of Ni into MA which was synthesized by a hydrothermal route and modification of the SGA based catalyst by W had positive effect on coke minimization.