Support structure-catalyst electroactivity relation for oxygen reduction reaction on platinum supported by two-dimensional titanium carbide

Abstract

It is demonstrated that the electroactivity of the oxygen reduction reaction (ORR) of Pt depends on the structure of a support. Highly conductive two-dimensional titanium carbide (Ti3C2) was selected as the support for Pt because of the expected strong metal-support interaction (SMSI) between Pt and Ti. To control the edge-to-basal ratio, the number of Ti3C2 layers was modulated by exfoliation. Pt nanoparticles (4 nm) were loaded on three different Ti3C2 supports including multi-, few-, and mono-layered Ti3C2 (22L-, 4L-, and 1L-Ti3C2, respectively). The edge-to-basal ratio of layered Ti3C2 increased as the number of layers increased. The edge-dominant support (22L-Ti3C2) donated more electrons to Pt than the basal-dominant supports (4L-Ti3C2 and 1L-Ti3C2). As a result, electron-rich Pt with less d-band vacancies (e.g., Pt/22L-Ti3C2) showed higher ORR activity. In addition, the electron transfer from the support to Pt inducing the strong interaction between Pt and Ti improved the durability of the ORR electroactivity of Pt.