Tungsten Promoted Ni/Al_2O_3 Catalysts for Carbon Dioxide Reforming of Methane to Synthesis Gas

摘要

A series of tungsten promoted alumina supported nickel catalysts has been prepared for the carbon dioxide reforming of methane to synthesis gas.The catalysts have been characterized by means of XRD,TEM,and Laser Raman spectroscopy.It is shown that the addition of tungsten to the nickel catalyst can stabilize the catalyst and increase the resistance to carbon deposition.Adding a suitable amount of tungsten can also increase the catalyst activity to be close to that of supported noble metal catalysts.The carburisation of the tungsten modified nickel catalyst decreases the catalyst activity at lower reaction temperatures(<1123K),but has no effect on the catalyst performance at higher reaction temperatures.The alumina supported nickel catalyst modified by 0.67%(mass fraction)WO_3 has the equivalent equilibrium constant of the dry reforming reaction to that of alumina supported 5%(mass fraction)Ru at 873 K,and also has a lower activation energy for dry reforming than the latter.