Potassium-doped Ni-MgO-ZrO2 catalysts for dry reforming of methane to synthesis gas

摘要: Ni/K–MgO–ZrO2 catalysts for dry reforming of methane, with a range Mg/Zr ratios and each containing about 10 wt% Ni, were prepared via Ni nitrate impregnation on MgO–ZrO2 supports synthesized by co-precipitation using K2CO3. It was found that proportion the potassium precipitant remained in samples improved stability reaction. also shown reduction at 1,023 K without calcination air is necessary stable high activity; 1,073 gives deterioration catalytic properties, leading to rapid deactivation during The order CH4 conversions reduced after 14 h stream as follows: Ni/K–Mg5Zr2 ~ Ni/K–Mg ≥ Ni/K–Mg2Zr5 ≫ Ni/K–Zr. A catalyst 0.95 Mg:Zr mole ratio 5:2 showed best resistance deactivation. Experiments microbalance system there only negligible coke deposition surface this sample. This behaviour attributed presence nanoparticles diameter less than nm located MgO/NiO solid solution shell doped ions; turn covers core tetragonal ZrO2 and/or MgO/ZrO2 solution. conclusion supported EDS/TEM, XPS, XRD H2 chemisorption measurements.