Tailoring Surface Adsorption and Reactivity of Fullerene-Based Compounds: A Theoretical Probe into C₂–Gas–Fullerene Surface Interactions

Abstract

Density functional theory investigations of palladium and nickel substituted fullerenes (C59M; M = Pd/Ni) were carried out probing the changes in their surface adsorption potential. Structure and bonding in the proposed heterofullerenes were established with insights into metal–carbon bond character, stability, and adsorption potential. C2‑gases were used as probe gases for adsorption tests. Adsorption of acetylene, ethylene, and ethane was studied with different sites over pure and heterofullerenes. Adsorption of acetylene was stronger than the adsorption of ethylene and ethane over C60 with the bridge site sharing hexagonal rings being the energetically favored adsorption site. Surface modification of the fullerene molecule with a foreign metal enhanced the gas-substrate (C2-heterofullerene) interactions. Enhanced surface interactions and differential adsorption behavior of different heterofullerenes made them potential candidates as selective acetylene hydrogenation catalysts. Free energy landscapes for hydrogenation of acetylene and ethylene over all three compounds were developed. The energy barriers for various elementary steps during hydrogenation were significantly smaller over the heterofullerenes when compared to those over C60. Whereas substitution of either metals resulted in a reduction of activation barriers, the activation barriers for post-ethylene formation reactions were smaller over C59Ni making C59Pd a good selective acetylene hydrogenation catalyst.

Computational Design of New Heterofullerene‐Based Biomimetic α‐Carbonic Anhydrase Analogues

“…Whereas conventional methods of dispersion by using van der Waals forces may not prove to be effective for fullerenes, anchoring of heterofullerenes to a substrate through covalent bonding with the help of organic ligands can prove to be effective . This technique can be considered to be fruitful in light of the fact that the activity of heterofullerenes is governed mainly by the sites close to the heteroatoms …”

“…[44] This technique can be considered to be fruitful in light of the fact that the activity of heterofullerenes is governed mainlyb yt he sites close to the heteroatoms. [45]…”