TY - JOUR
T1 - Comparative analysis of NOx reduction on Pt, Pd, and Rh catalysts by DFT calculation and microkinetic modeling
AU - Lee, Min Woo
AU - Lee, Eun Jun
AU - Lee, Kwan Young
N1 - Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP; NRF-2016R1A5A1009592).
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2023/2/15
Y1 - 2023/2/15
N2 - In this study, adsorption energies and reaction energetics on (1 1 1) surfaces of Pt, Pd and Rh were established using DFT calculation. Based on these thermodynamic results, reactant conversions and product yields of Pt, Pd and Rh catalysts under various air–fuel ratio (λ) were predicted by microkinetic modeling combined with simulated packed bed reactor. As a result, Pt catalyst efficiently utilizes H2 in assisting NO dissociation and removing surface O* under stoichiometric and fuel-lean conditions. However, it presents high NH3 yield under stoichiometric and fuel-lean conditions. Conversely, Rh catalyst show high NO reduction activity under fuel-rich condition while it hardly reduce NO in presence of O2. In order to take the advantages of both catalysts, we suggest physically-mixed Rh + Pt catalyst is excellent catalyst using the advantages of each catalyst for TWC. Consequently, it is confirmed that Pt sufficiently reduces NO using H2 under stoichiometric and fuel-lean conditions, and Rh easily dissociates NO at low temperature under fuel-rich condition when using the Rh + Pt catalyst. We expect that identifying the reaction characteristics of TWC components under different λ conditions will help to propose future TWC design.
AB - In this study, adsorption energies and reaction energetics on (1 1 1) surfaces of Pt, Pd and Rh were established using DFT calculation. Based on these thermodynamic results, reactant conversions and product yields of Pt, Pd and Rh catalysts under various air–fuel ratio (λ) were predicted by microkinetic modeling combined with simulated packed bed reactor. As a result, Pt catalyst efficiently utilizes H2 in assisting NO dissociation and removing surface O* under stoichiometric and fuel-lean conditions. However, it presents high NH3 yield under stoichiometric and fuel-lean conditions. Conversely, Rh catalyst show high NO reduction activity under fuel-rich condition while it hardly reduce NO in presence of O2. In order to take the advantages of both catalysts, we suggest physically-mixed Rh + Pt catalyst is excellent catalyst using the advantages of each catalyst for TWC. Consequently, it is confirmed that Pt sufficiently reduces NO using H2 under stoichiometric and fuel-lean conditions, and Rh easily dissociates NO at low temperature under fuel-rich condition when using the Rh + Pt catalyst. We expect that identifying the reaction characteristics of TWC components under different λ conditions will help to propose future TWC design.
KW - Density functional theory
KW - Microkinetic modeling
KW - NO reduction
KW - Platinum-group metal
KW - Three-way catalyst
UR - http://www.scopus.com/inward/record.url?scp=85141919463&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2022.155572
DO - 10.1016/j.apsusc.2022.155572
M3 - Article
AN - SCOPUS:85141919463
SN - 0169-4332
VL - 611
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 155572
ER -