TY - JOUR
T1 - Comparing B3LYP and B97 Dispersion-corrected Functionals for Studying Adsorption and Vibrational Spectra in Nitrogen Reduction
AU - Grossman, Esther F.
AU - Daramola, Damilola A.
AU - Botte, Gerardine G.
N1 - Funding Information:
This research was supported by the Ohio Supercomputer Center under grant number OSC‐PHS0269, the Ohio University Honors Tutorial College, and the Center for Electrochemical Engineering Research.
Publisher Copyright:
© 2021 The Authors. Published by Wiley-VCH GmbH
PY - 2021/3
Y1 - 2021/3
N2 - Electrochemical ammonia synthesis is being actively studied as a low temperature, low pressure alternative to the Haber-Bosch process. This work studied pure iridium as the catalyst for ammonia synthesis, following promising experimental results of Pt-Ir alloys. The characteristics studied include bond energies, bond lengths, spin densities, and free and adsorbed vibrational frequencies for the molecules N2, N, NH, NH2, and NH3. Overall, these descriptive characteristics explore the use of dispersion-corrected density functional theory methods that can model N2 adsorption – the key reactant for electrochemical ammonia synthesis via transition metal catalysis. Specifically, three methods were tested: hybrid B3LYP, a dispersion-corrected form B3LYP-D3, and semi-empirical B97-D3. The latter semi-empirical method was explored to increase the accuracy obtained in vibrational analysis as well as reduce computational time. Two lattice surfaces, (111) and (100), were compared. The adsorption energies are stronger on (100) and follow the trend EB3LYP>EB3LYP-D3>EB97-D3 on both surfaces.
AB - Electrochemical ammonia synthesis is being actively studied as a low temperature, low pressure alternative to the Haber-Bosch process. This work studied pure iridium as the catalyst for ammonia synthesis, following promising experimental results of Pt-Ir alloys. The characteristics studied include bond energies, bond lengths, spin densities, and free and adsorbed vibrational frequencies for the molecules N2, N, NH, NH2, and NH3. Overall, these descriptive characteristics explore the use of dispersion-corrected density functional theory methods that can model N2 adsorption – the key reactant for electrochemical ammonia synthesis via transition metal catalysis. Specifically, three methods were tested: hybrid B3LYP, a dispersion-corrected form B3LYP-D3, and semi-empirical B97-D3. The latter semi-empirical method was explored to increase the accuracy obtained in vibrational analysis as well as reduce computational time. Two lattice surfaces, (111) and (100), were compared. The adsorption energies are stronger on (100) and follow the trend EB3LYP>EB3LYP-D3>EB97-D3 on both surfaces.
KW - ammonia adsorption
KW - ammonia synthesis
KW - density functional calculations
KW - dispersion methods
KW - iridium
UR - http://www.scopus.com/inward/record.url?scp=85099278518&partnerID=8YFLogxK
U2 - 10.1002/open.202000158
DO - 10.1002/open.202000158
M3 - Article
C2 - 33434349
AN - SCOPUS:85099278518
VL - 10
SP - 316
EP - 326
JO - ChemistryOpen
JF - ChemistryOpen
SN - 2191-1363
IS - 3
ER -