Propane dry reforming to synthesis gas over Ni-based catalysts: Influence of support and operating parameters on catalyst activity and stability

A series of supported Ni catalysts (∼2 wt% Ni) were tested for the dry reforming of propane to synthesis gas reaction at 600 °C, C 3H 8:CO 2:H 2:N 2 (%) = 10:30:10:50, 1 atm and GHSV = 13333 Nml/(h g cat). The support systems studied range from acidic (SiO 2) to amphoteric [Al 2O 3, Mg(Al)O] to basic oxides [MgO, CaO], with BET areas of 100, 100 (131 and 173), 117, and 16 m 2/g, respectively. Ni particle size and reduction state was investigated by magnetic measurements, performed before and during catalytic testing. Support basicity was measured by CO 2 TPD. It was observed that the intrinsic activity of the catalysts (TOF) depends strongly on the Ni particle size ( D) in the size range of 4.5–11 nm. As such, a TOF versus D plot showed an exponential inverse relationship, much more pronounced than previously reported for the methane dry reforming reaction. In turn, a volcano-type correlation was found between intrinsic catalyst activity and support basicity. As a result, the best catalytic performance, including a low selectivity to methane, was observed on the most dispersed Ni particles supported on Mg(Al)O. Key mechanistic features were derived from these observations.