Covalent Organic Framework Supported Single Atom Catalyst for Hydrogen Evolution Reaction: A Theoretical Investigation

Abstract

Global environmental considerations are being raised as a result of excessive fossil fuel consumption and excessive carbon dioxide (CO2) emission. Regrettably, fossil fuel reserves are decreasing, and energy generation from them is unsustainable, non-renewable, and unaffordable. Due to these concerns, there is an imperative demand for sustainable and eco-friendly energy conversion electrochemical systems. Hydrogen (H2) is ubiquitously regarded as a future sustainable energy source and an attractive alternative to conventional fossil fuels. Production of hydrogen must be sustainable in order for a hydrogen economy to thrive in the future. Water electrolysis powered by renewable resources is being considered as a sustainable approach to produce hydrogen. In attempt to implement the process of water splitting efficiently, cost-effective, and non-precious metal based electrocatalysts for hydrogen evolution reaction (HER) are required. The development of effective single-atom catalysts (SACs) for electrochemical water splitting is a viable technique. High energy barrier of the HER and a catalyst with low stability continue to pose difficulties for the entire process of water splitting. To address this issue, electrocatalysts with single metal atoms supported on a covalent organic framework (TM@COF SACs) have been proposed for HER. The catalytic performance of these catalysts for HER is determined by the change in the Gibbs free energy of adsorbed atomic hydrogen (ΔGH*) on the catalyst's surface. Density functional theory (DFT) findings suggest that the Zn single atom doped on the surface of the covalent organic framework has a significant impact on the HER performance. This study paves the way for the development and use of highly efficient, stable, and non-precious single atom HER catalysts.