The electronic properties, stability and catalytic activity of metallofullerene (M@C60) for robust hydrogen evolution reaction: DFT insights

The development of low-cost, and highly active catalysts for electrocatalytic hydrogen evolution process is of great interest. Exohedral first row transition metal doped fullerenes based single atom catalysts (SACs) are expected to replace precious metal catalysts for sustainable and large-scale commercial scalability of hydrogen generation. Herein, a series of ten metal (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu & Zn) single atoms doped C60 fullerenes (metallofullerenes) are screened for hydrogen evolution reaction. All the studied metallofullerenes are optimized with the various possible spin states and the most stable spin states among them are selected for further analysis. The stability of electrocatalysts is evaluated via interaction energy analysis, which reveals that all the designed metal-lofullerenes are thermodynamically stable (-0.24 to -4.30 eV). The hydrogen adsorption (Eads) and Gibbs free energy results reveal that Fe@C60 complex has the best catalytic activity for hydrogen evolution process with optimal DGH value of 0.08 eV. FMO analysis declares appreciable variations in electronic properties of C60 fullerene upon doping. Moreover, density of states (DOS) analysis also corroborates with FMO analysis for designed metallofullerene (M@C60) catalysts and HM@C60 complexes. Exchange current density is plotted as a function free energy (DGH) for hydrogen evolution process over designed metallofullerene. The volcano plot reveals the near thermoneutral behavior of Fe@C60 catalyst for hydrogen evolution reaction. Overall, results presented here for systematic screening of potential HER from metallofullerene based single atom catalysis can remarkably contribute to the design and fabrication of electrocatalysts.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.