Computational modeling of the Nb\(_4\)-CO chemisorption process

Abstract

Context

The transition metal niobium (Nb) has attracted considerable attention from the scientific community due to its intriguing electronic properties and applications in catalysts suitable for chemical reactions. Thus, this work investigates the adsorption of the atmospheric polluting gas carbon monoxide (CO) by the niobium cluster (Nb\(_4\)), to describe the reactive nature of Nb\(_4\). This entire study was carried out by applying the Coupled-Cluster method and Density Functional Theory (through the HSE06 functional) and the def2-QZVP plus Def2-TZVP/C auxiliary basis set functions. The results of electronic structure calculations and IR vibrational spectra suggest that both Nb\(_4\) and the Nb\(_4\)-CO clusters can be considered stable. Furthermore, the obtained results also indicate that there is a chemisorption of carbon monoxide by the Nb\(_4\) niobium cluster. This feature can serve as motivation for future theoretical–experimental studies, as it suggests that the Nb\(_4\) cluster may have possible technological applications in automotive catalytic processes.

Methods

Initial three-dimensional structures were constructed. Complete optimization of the geometry was performed in coupled cluster and density functional theory methods. From the optimization configuration, it was possible to investigate the stability, chemisorption process, binding energies, charge analysis, molecular orbital energies, and IR vibrational spectra of the systems.