High Catalytic Stability of Porous α-Al2O3-Supported Ni Catalyst in Fluidized-Bed Dry Reforming at Extremely High Space Velocity

Abstract Two Ni catalysts supported on nearly spherical porous α-Al2O3 particles with a low attrition rate of 0.0008 wt %/h were prepared, using an incipient wetness impregnation method, and were tested for the dry reforming of methane in a fluidized bed reactor at 800 °C and high space velocities. Characterization using XRD and mercury intrusion porosimetry of the support and the two catalysts with, respectively, 3 wt % Ni and 10 wt % Ni revealed that most of the loaded Ni species in the catalysts were dispersed in their support’s macropores. Meanwhile, the results of the short-term comparative reforming tests confirmed that the catalyst with 10 wt % Ni has a considerably higher volume activity that the 3 wt % Ni-loaded catalyst. Additionally, the result of a 105-h long-term discontinuous reforming test at an extremely high space velocity of 120 L/(g·h) and TG measurement of the spent catalyst sample together confirmed that the 10 wt % Ni-loaded catalyst enables to provide a highly stable catalytic activity throughout the whole test period without carbon deposition accompanied. Moreover, TEM observation of a spent 10 wt % catalyst sample recovered from the long-term test confirmed that Ni nanoparticles loaded in the support’s macropores are considerably resistant to sintering. All these together demonstrate that porous α-Al2O3 supported Ni catalyst is highly applicable for the fluidized-bed methane reforming.