High-density single-atom electrocatalytic centers on two-dimensional topological platinum tellurides with Te-vacancy superstructure

TL;DR

This paper reports a novel topological platinum telluride catalyst with high-density single-atom centers on a superstructure, showing enhanced hydrogen evolution reaction performance and stability, confirmed by experiments and first-principles calculations.

Contribution

Introduction of a (7x7)-PtTe2-x superstructure with high-density single-atom reactive centers exhibiting superior HER activity and stability, and demonstration of its nontrivial band topology.

Findings

(7x7)-PtTe2-x outperforms pristine and other PtTe2 forms in HER.

High density of undercoordinated Pt sites enhances catalytic activity.

The material exhibits nontrivial topological properties with robust edge states.

Abstract

Chemical activation of the intrinsically inert basal planes of transition metal dichalcogenides (TMDs) is crucial for developing high-efficiency electrocatalysts for energy technology applications. Here we report the discovery of an efficient TMD-based topological catalyst for hydrogen evolution reaction (HER), containing high-density single-atom reactive centers on a few-layer (7x7)-PtTe2-x superstructure with a Te-vacancy density of x. Compared with pristine Pt(111), PtTe2, and (2x2)-PtTe2-x, (7x7)-PtTe2-x exhibits superior HER performance owing to its substantially increased density of undercoordinated Pt sites, and displays exceptional catalytic stability when operating at high current densities. Our first-principles calculations confirm that multiple types of undercoordinated Pt sites on (7x7)-PtTe2-x exhibit favorable hydrogen adsorption Gibbs free energies, and that the reactive sites can further increase their population upon increasing hydrogen coverage. Both the (2x2)- and (7x7)-PtTe2-x are also shown to possess nontrivial band topology with robust edge states that may further facilitate HER.