Magnetic Susceptibility, Proton NMR and Muon Spin Rotation (μSR) Studies of an Unsupported Platinum Catalyst with Adsorbed H and O
The effects of adsorbed H and O upon the strong intrinsic magnetism exhibited by small particles of platinum have been studied by magnetic susceptibility measurements, proton NMR and muon spin rotation. All work to date has been on very pure samples of an unsupported Pt catalyst prepared by chemical reduction techniques. Dispersions of the samples are in the range.12–.20. The effect of adsorbed H is slight, but O increases the Curie-Weiss susceptibility of the catalysts substantially at low temperatures. H, however, sharply decreases both the spin-lattice relaxation rate of protons in the samples, whose NMR signals are observable at 4.2K, and the transverse field relaxation rate of muons stopped in the samples.
KeywordsMagnetic Susceptibility Relaxation Rate Magnetic Susceptibility Measurement Paramagnetic Impurity Platinum Black
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