Fullerene Negative Ions: Formation and Catalysis

Abstract

We first explore negative-ion formation in fullerenes C44, C60, C70, C98, C112, C120, C132 and C136 through low-energy electron elastic scattering total cross sections calculations using our Regge-pole methodology. Water oxidation to peroxide and water synthesis from H2 and O2 are then investigated using the anionic catalysts C44ˉ to C136ˉ. The fundamental mechanism underlying negative-ion catalysis involves hydrogen bond strength-weakening in the transition state. DFT transition state calculations found C60ˉ numerically stable for both water and peroxide synthesis, C100ˉ increases the energy barrier the most and C136ˉ the most effective catalyst in both water synthesis and oxidation to H2O2.

Conundrum in Measured Electron Affinities of Complex Heavy Atoms

“…This value is in outstanding agreement with the values calculated using the Regge pole [2] and MCDF-RCI [3] methods. Previously, the EA of Eu was measured to be 1.053 ± 0.025 eV [4], which agrees very well with the Regge pole value of 1.08 eV [5]. Here we have a conundrum because an atom can have only a single EA value.…”

Recent Progress in Low-Energy Electron Elastic-Collisions with Multi-Electron Atoms and Fullerene Molecules

“…The electron elastic TCSs for the typical large fullerenes C 100 , C 120 and C 140 demonstrate negative-ion formation [92,93,94] with significant differences among their EAs, namely 3.67eV, 3.74eV and 3.94eV, respectively, see also Table 3.2. It is now clear that the ground state anionic BEs located at the absolute R-T minima of the ground state TCSs yield the challenging to calculate theoretically EAs.…”

“…The utility of the generated fullerene anions has been demonstrated in the catalysis of water oxidation to peroxide and water synthesis from H 2 and O 2 using the anionic fullerene catalysts C 20 ˉ to C 136 ˉ. [92]. Figures 3.6 taken from [92] demonstrate the Density Functional Theory (DFT) calculated TS energy barriers for both processes.…”

“…[92]. Figures 3.6 taken from [92] demonstrate the Density Functional Theory (DFT) calculated TS energy barriers for both processes. DFT and dispersion corrected DFT approaches have been employed for the TS evaluations.…”

“…More recently, the experiment [89] has used the less expensive atomic Sn for possible water purification in the developing world. In this context we explored [92] the effectiveness of the fullerene anions C 20 ˉ to C 136 ˉ in the catalysis of water oxidation to peroxide and water synthesis from H 2 and O 2 hoping to find inexpensive effective negative-ion catalysts.…”