Electrocatalytic activity of the 2D monolayer of PtS2 and Pt@PtS2 towards O2 reduction reaction

Abstract

The oxygen reduction reaction (ORR) is crucial in electrochemical energy conversion devices like fuel cells. Though vital to the performance of the fuel cell, it is very sluggish, highlighting the need for research focused on electrocatalysts and enhancing their effectiveness for developing high-activity and low-price electrocatalysts. In the same pursuit, this thesis computationally explored the ORR catalytic activity of the 2D monolayer PtS2 and Pt atom anchored on the 2D monolayer PtS2 (i.e., 2D monolayer Pt@PtS2). The first-principles density functional theory (DFT-D3) calculations have been employed to study the electronic, structural, and ORR catalytic properties of the 2D monolayer of PtS2 and Pt@PtS2. Electronic structure calculations revealed that the 1T PtS2 monolayer has an indirect band gap of 2.97 eV, which reduces to an indirect band gap of 1.23 eV after the introduction of a Pt atom on the 2D monolayer PtS2 (Pt@PtS2), indicating the excellent electronic properties of the Pt@PtS2 and its potential as an ORR electrocatalyst. In this thesis, the four-electron associative and dissociative reaction pathways were explored by calculating the adsorption energies (ΔE) of each of the intermediates involved. The dissociative pathway is found to be favorable for the 2D monolayer PtS2, while the associative pathway is found to be favorable for 2D monolayer Pt@PtS2. This study concludes that the 2D monolayer Pt@PtS2 can act as an excellent ORR catalyst for the application in the fuel cells.