The performances of Ni-MgO@-Al₂O₃ for steam methane reforming prepared by freeze-drying technology

Ni-based catalysts are an indispensable part for methane reforming, but the catalyst deactivation occurs at high reforming temperatures due to coke deposition and sintering. In this work, co-impregnation and freeze drying method was developed to prepare the Ni-based catalyst which were characterized by XRD, TEM and H-2-TPR. And the effects of freeze drying method and MgO on CH4 conversion, H-2 yield and CO selectivity were investigated. The results revealed that the application of the freeze-drying method promoted the dispersion of Ni particles on the surface of gamma-Al2O3 support. Moreover, the inclusion of MgO further enhanced Ni dispersion and suppressed the particle size of the catalysts. Among the prepared catalysts, the 0.05MgO-Ni/gamma-Al2O3 catalyst showed the best catalytic performance. CH4 conversion, H-2 yield and CO selectivity respectively exceeded 75%, 55% and 90% under the conditions of an S/C ratio of 2 and reforming temperature of 600 degrees C after 10 h.