Electro‐Oxidation of Polyols on Bi‐Modified Pt in Acidic Media (HClO4). 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. The electro‐oxidation of glycerol on different Pt surfaces with/without Bi‐modification was studied through electrochemical, in situ FTIR and DFT experiments to understand the effect of the surface on the activity and selectivity. We show that the oxidation of the secondary carbon is more likely to occur on more coordinated Pt atoms and how the selectivity is enhanced in the presence of Bi species.