An analysis of electroless deposition derived Ni-Pt catalysts for the dry reforming of methane

A series of nickel-platinum catalysts supported on gamma alumina (gamma-Al2O3) with small, increasing amounts of Pt promoter were precisely prepared by electroless deposition at 5.0 wt% Ni and with compositions up to 2.8 wt% Pt (one theoretical monolayer of Pt on Ni) and evaluated for the dry reforming of methane. Characterization was performed using x-ray diffraction, temperature programmed reduction, scanning transmission electron microscopy, and temperature programmed oxidation. At temperatures below 600 degrees C, activity of bimetallic samples exhibited a maximum at 0.4 monolayers Pt and surpassed that of unpromoted Ni. At 700 degrees C, deactivation occurred for all samples. X-ray diffraction patterns of the high-temperature treated catalysts indicated segregation of the Ni-Pt alloys. Pt showed no influence on hydrogen selectivity, which was driven by thermodynamic limits. (C) 2019 Elsevier Inc. All rights reserved.