Interstitial-Electrons Composed Multiple-Fold Fermions and Insights on Catalytic Nature in Nanoporous Electride C12A7:e$^-$
Year: 2021
Type: preprint
Abstract: Nanoporous 12CaO$\cdot$Al$_2$O$_3$ (C12A7:e$^-$), known as a famous electride and electron source material, was recently proposed to boost catalytic activity in C12A7:e$^-$ based catalysts. However, the fundamental mechanism on such catalytic enhancement keeps in debate currently. Here, by means of symmetry analysis and first-principles calculations, we discover that this famous electride material, surprisingly, hosts interstitial-electrons composed multiple-fold fermions that helps to understand the catalytic nature of C12A7:e$^-$ based catalysts. The multiple-fold fermions contain a sixfold- and a fourfold- degenerate point, locating at high symmetric points near the Fermi energy. Remarkably, comparing with traditional Weyl/Dirac fermions, the multiple-fold fermions are found to show extremely longer Fermi arcs on the C12A7:e$^-$ (001) surface. As the result, this surface is highly active and carries a relatively low Gibbs free energy ($\Delta \rm G_{H^*} = 0.24$ eV) during the catalytic process. This G is also much lower than typical Weyl/Dirac catalysts proposed previously. This work offers a guiding principle for understanding catalytic nature of electrides and topological quantum catalysts as well.
Source: arXiv (Cornell University)
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3143044338