Electro-Oxidation of Polyols on Bi-Modified Pt in Acidic Media (HCl™O4). Understanding Activity and Selectivity Trends

Herein we show that Pt(111) and Pt(100) can produce the ketone through the oxidation of the secondary carbon of the polyols. After the Bi modification, the selectivity for the ketone formation increases. On the other hand, we observe that pure and Bi-modified Pt(110) only produced the C3 molecules oxidized in the primary carbon, and it is the only facet that shows an enhancement in the activity due to the modification. In line with these findings, small Pt nanoparticles are not selective for ketone formation. Finally, based on data obtained through DFT calculations, we suggest that positively charged Bi adatoms interact with the OH- groups of the enediol-like intermediate (believed to be the precursor for the ketone/aldehyde production), facilitating the oxidation of the secondary carbon to produce DHA.

Automated summary

We demonstrate that Pt(111) and Pt(100) can catalyze the oxidation of the secondary carbon of polyols to produce ketones. The addition of Bi increases the selectivity for ketone formation. In contrast, pure and Bi-modified Pt(110) only yield C3 molecules with oxidation on the primary carbon, but Bi modification enhances the activity. DFT calculations suggest that positively charged Bi adatoms facilitate the oxidation of the secondary carbon in the enediol-like intermediate, leading to the production of DHA.