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

Abstract

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.

Highly Durable Platinum Single‐Atom Alloy Catalyst for Electrochemical Reactions

“…It is known that the electrocatalytic MOR necessitates Pt ensemble sites. [3] As shown in Figure 3c, the Pt1/ATO without Pt ensemble sites showed no activity for MOR. Instead, the Pt/C showed the highest Pt mass activity.…”

“…The Pt1/ATO exhibited exceptionally high activity for FAOR but no activity for MOR; this also confirms the presence of single atomic Pt sites without Pt nanoparticles. [3,12] The electrocatalytic ORR can follow two pathways, a two electrons path (O 2 + 2H + + 2e − → H 2 O 2 ) and a four electrons path (O 2 + 4H + + 4e − → 2H 2 O). The former reaction can occur on single atomic Pt, but the latter necessitates Pt ensemble sites to cleave the OO bond.…”

“…[1][2][3] For example, single atomic Pt immobilized on FeO x has high activity for the preferential oxidation of CO and high chemoselectivity for nitroarene hydrogenation. [2,4] Single atomic Pt on θ-Al 2 O 3 showed high activity for www.advenergymat.de www.advancedsciencenews.com electronic or geometric structure.…”

“…[2,4] Single atomic Pt on θ-Al 2 O 3 showed high activity for www.advenergymat.de www.advancedsciencenews.com electronic or geometric structure. [3,25,26] Among various strategies, a single atomic Pt structure would have high activity and selectivity in the FAOR, because only 1-2 Pt atoms are required for the direct path, while Pt ensemble sites are required for the indirect path. [24] In this work, antimony-doped tin oxide (ATO) was selected as a support for the single atomic Pt electrocatalyst because of its strong interaction with Pt, high electronic conductivity, and high corrosion resistance in an acidic environment.…”

“…[4] We also reported that single atomic Pt supported on TiN and TiC showed high selectivity to the production of H 2 O 2 in the electrocatalytic oxygen reduction reaction (ORR). [3,5] However, although the atomically dispersed catalysts have shown great potential for various heterogeneous reactions, there are still issues to be solved. They have been usually prepared with very low loadings, <1 wt%, and their durability is often poor due to intrinsically unstable nature of the single atomic structure.…”