Ordered PtPb/Pt Core/Shell Nanodisks as Highly Active, Selective, and Stable Catalysts for Methanol Reformation to H₂

Herein, we report on unique bimetallic PtPb/Pt core/shell nanodisks consisting of structurally ordered PtPb hexagonal nanoplates as the core and the well-organized Pt as the shell, as extremely active and selective catalysts towards CH₃OH reformation. We found that the created Pt-Pb nanodisks/C show the composition-dependent activity with the optimized PtPb_0.56 nanodisks/C being the most active for the CH₃OH reformation to H₂, 5.1 times higher than those of the commercial Pt/C. Significantly, only very limited carbon monoxide (CO) is produced during the CH₃OH reformation, which is crucial for the practical application in fuel cells. The PtPb_0.56 nanodisks/C is also more active for CH₃OH reformation than PtPb hexagonal nanoplates/C and PtPb_0.58 nanoparticles/C. X-ray photoelectron spectroscopy (XPS) results reveal that the high ratio of Pt (0) to Pt (II) in Pt-Pb nanodisks/C enhances the CH₃OH reformation to H₂, while the high content of Pb (0) is beneficial for decrease the CO production. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) of CO adsorption shows that Pt-Pb nanodisks can promote the activation of CO molecules by forming the carboxylate (CO₂ ^{δ −}) intermediates, leading to the low CO production.