H2 Adsorption on Small Pd-Ni Clusters Deposited on N-Doped Graphene: A Theoretical Study

Abstract

The study of novel materials for H2 storage is essential to consolidate the hydrogen as a clean energy source. In this sense, the H2 adsorption on Pd4-nNin (n = 0–3) clusters embedded on pyridinic-type N-doped graphene (PNG) was investigated using density functional theory calculations. First, the properties of Pd4-nNin (n = 0–3) clusters embedded on PNG were analyzed in detail. Then, the H2 adsorption on these composites was computed. The Eint between the Pd4-nNin (n = 0–3) clusters and the PNG was greater than that computed in the literature for Pd-based systems embedded on pristine graphene. Consequently, it was deduced that PNG can more significantly stabilize the Pd4-nNin (n = 0–3) clusters. The analyzed composites exhibited a HOMO–LUMO gap less than 1 eV, indicating good reactivity. Based on the Eads of H2 on Pd4-nNin (n = 0–3) clusters embedded on PNG, it was observed that the analyzed systems meet the standards set by the DOE. Therefore, these composites can be viable alternatives for hydrogen storage.