Investigation of the cyclo[12]carbon nanoring and respective analogues (Al6N6 and B6N6) as support for the single atom catalysis of the hydrogen evolution reaction

Nowadays, the pursuit of finding suitable supports for single atom catalysts (SACs) is rising in interest. Novel carbon-based nanostructures are most promising due to their unique properties such as high surface area, excellent stability, large degree of functionalization, and high electric conductivity. In this work, we investigated the potential application of late first-row transition metal doped cyclo [12]carbon (C12) nanoring and its isoelectric analogues (Al6N6, and B6N6) as SACs towards hydrogen evolution reaction (HER), via DFT calculations. Among all studied systems, Co@C12, Ni@C12, Cu@C12, and Ni@Al6N6 showed the highest electrocatalytic potential towards the HER, as they show excellent stabilities with high interaction energies of −3.41, −2.40, −1.19, and −3.05 eV, respectively. Furthermore, the results of the electronic properties analysis revealed that these systems are sufficiently conducting with small band gaps. The activities of the proposed catalysts were evaluated by computing the Gibbs free energy of hydrogen evolution (ΔGH*), which is the main activity descriptor of the HER. The best catalytic activities were obtained for Co@C12, Ni@C12, Cu@C12, and Ni@Al6N6, having ΔGH* values of −0.23, 0.23, −0.14, and 0.18 eV, respectively. This study will help in finding novel, noble metal-free, and highly efficient catalysts for producing high purity hydrogen gas.