Sungeun Yang

Single-Atom Catalyst of Platinum Supported on Titanium Nitride for Selective Electrochemical Reactions

As a catalyst, single-atom platinum may provide an ideal structure for platinum minimization. Herein, a single-atom catalyst of platinum supported on titanium nitride nanoparticles were successfully prepared with the aid of chlorine ligands. Unlike platinum nanoparticles, the single-atom active sites predominantly produced hydrogen peroxide in the electrochemical oxygen reduction with the highest mass activity reported so far. The electrocatalytic oxidation of small organic molecules, such as formic acid and methanol, also exhibited unique selectivity on the single-atom platinum catalyst. A lack of platinum ensemble sites changed the reaction pathway for the oxygen-reduction reaction toward a two-electron pathway and formic acid oxidation toward direct dehydrogenation, and also induced no activity for the methanol oxidation. This work demonstrates that single-atom platinum can be an efficient electrocatalyst with high mass activity and unique selectivity.

Production of acrylic acid from biomass-derived allyl alcohol by selective oxidation using Au/ceria catalysts

Acrylic acid is an important industrial chemical and it is currently produced from crude oil-derived propylene by selective oxidation. A new pathway for its more sustainable production has been suggested, from glycerol to allyl alcohol to acrylic acid. The selective oxidation of allyl alcohol to acrylic acid has been achieved in basic aqueous solution using a Au/ceria catalyst. The ways to enhance the selectivity towards acrylic acid have been sought by changing the kind of support, Au nanoparticle size, and Au oxidation states. We found that the Au oxidation state affected the selectivity significantly. Whereas the catalyst prepared by the colloidal deposition method contained mostly metallic Au and produced more 3-hydroxypropionic acid, the catalyst prepared by the deposition–precipitation method contained oxidic Au and produced more acrylic acid with the CC bond preserved.