Ab initio thermal rate coefficients for H + NH3 ⇌ H2 + NH2

Abstract

The reversible reaction NH3 + H ⇌ H2 + NH2, which plays an important role in NH3 fuel combustion, is studied with a theoretical approach that combines the high‐accuracy extrapolated ab initio thermochemistry (HEAT) protocol with semiclassical transition state theory (SCTST). The calculated forward reaction is endothermic by 11.8 ± 1 kJ/mol, in nearly perfect agreement with the active thermochemical tables (ATcT) value of 11.5 ± 0.2 kJ/mol. Using this improved thermochemistry yields better rate constants, especially at low temperatures. Experimental rate constants available from 400 to 2000 K for the forward and reverse reaction pathways can be reproduced (within 20%) by the calculations from first principles.

Document Details

Document Type
Pub Defense Publication
Publication Date
Feb 01, 2019
Source ID
10.1002/kin.21255

Entities

People

  • John F Stanton
  • Thanh L Nguyen

Organizations

  • Air Force Office of Scientific Research
  • National Science Foundation
  • United States Department of Energy
  • University of Florida

Tags

Readers

  • Combustion science or combustion engineering.
  • Quantum Chemistry
  • Systems Analysis and Design