(171b) Highly Selective H2 Production Via Methanol Steam Reforming Using Cu-MCM-41 Catalysts

Steam reforming of methanol was studied over a series of Cu-MCM-41 catalysts with Cu loading varied from 5% to 20% synthesized using one pot hydrothermal procedure. The catalysts were characterized using N₂ adsorption-desorption isotherms (BET), small and wide angle X-ray diffraction (XRD), thermo-gravimetric and differential calorimetric analysis (TGA-DSC), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), energy dispersive X-ray spectroscopy (EDX), electron paramagnetic resonance (EPR) and temperature programmed reduction (TPR) techniques. Small angle XRD and N₂ adsorption-desorption studies indicated the optimum loading of copper to be 15%, where the characteristic ordered structure of the MCM-41 was retained with high specific surface of about 662 m²/g. The catalysts exhibited outstanding activity, selectivity and stability for steam reforming of methanol (SRM) reactions. The activity and selectivity of the Cu-MCM-41 catalysts were significantly influenced by the Cu-loading and the reaction temperature. The SRM results revealed that 15%Cu-MCM-41 showed optimum performance in terms of methanol conversion (~ 90%), H₂ selectivity (100%) and CO selectivity (0.79%) at 300 °C. While both the reactant space velocity and methanol/water molar ratio strongly influenced the activity of the catalysts, selectivity of the catalysts remained unaffected. The Cu-MCM-41catalyst showed strong resistance to deactivation and maintained consistent performance over a period of 48 h. The excellent stability of the catalyst in the SRM reaction can be attributed to the uniform distribution of the Cu particles in a very high surface area MCM-41 matrix, inhibiting the sintering of Cu particles. The highlights of this work will be discussed in the presentation.