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Combining in Situ NEXAFS Spectroscopy and CO2 Methanation Kinetics To Study Pt and Co Nanoparticle Catalysts Reveals Key Insights into the Role of Platinum in Promoted Cobalt Catalysis
journal contribution
posted on 2014-07-16, 00:00 authored by Simon
K. Beaumont, Selim Alayoglu, Colin Specht, William D. Michalak, Vladimir
V. Pushkarev, Jinghua Guo, Norbert Kruse, Gabor A. SomorjaiThe
mechanistic role of platinum and precious metals in promoting
cobalt hydrogenation catalysts of the type used in reactions such
as Fischer–Tropsch synthesis is highly debated. Here we use
well-defined monometallic Pt and Co nanoparticles (NPs) and CO2 methanation as a probe reaction to show that Pt NPs deposited
near Co NPs can enhance the CO2 methanation rate by up
to a factor of 6 per Co surface atom. In situ NEXAFS spectroscopy
of these same Pt NP plus Co NP systems in hydrogen shows that the
presence of nearby Pt NPs is able to significantly enhance reduction
of the Co at temperatures relevant to Fischer–Tropsch synthesis
and CO2 methanation. The mechanistic role of Pt in these
reactions is discussed in light of these findings.