Understanding the role of boron and stoichiometric ratio in the catalytic performance of amorphous Co-B catalyst
Abstract
The structural, electronic and hydrogen adsorption properties of amorphous CoB, Co2B and Co3B structures were investigated using first principle calculations to evaluate their catalytic activity for HER. A total of eight different sites were considered for hydrogen adsorption, of which the threefold site with two Co and single B atom (TF-2Co-B) was found to be most active site for all the three amorphous Co-B structures. The B atom donates electronic charge to the Co-B bond, while, the presence of Co atom is responsible for achieving the optimal charge density necessary for favorable hydrogen adsorption. This interaction between the Co and B atoms makes bonding region between the Co and B atoms most favorable for hydrogen adsorption and not lone Co atom nor the B atom, thus, determining the active sites of Co-B catalyst. The best catalytic behavior of Co2B stoichiometry was credited to the perfect balance of magnetic properties, optimum hydrogen adsorption energies and considerable number of active sites it displayed.
- Publication:
-
Applied Surface Science
- Pub Date:
- July 2020
- DOI:
- 10.1016/j.apsusc.2020.146199
- Bibcode:
- 2020ApSS..51846199K
- Keywords:
-
- Ab-initio calculation;
- Density functional theory;
- Amorphous electrocatalyst;
- Transition metal boride;
- Hydrogen adsorption energies;
- Cobalt boride