13780-28-4

Upstream product

• 15123-00-9 imidogen 
• 13550-49-7 ammonia-d3 
• 7727-37-9 nitrogen 
• 1333-74-0 hydrogen 
• 16873-17-9 deuterium 
• 7789-20-0 water-d2 
• 7664-41-7 ammonia 

Downstream Products

• 15117-75-6 deuteroimine 
• 15117-84-7 ⁽²⁾H₂N 
• 14940-63-7 water 
• 113321-75-8 H⁽²⁾H₂N⁽¹⁸⁾O 
• 113321-77-0 H⁽²⁾H₂N⁽¹⁸⁾O 
• 113321-76-9 H₂⁽²⁾HN⁽¹⁸⁾O 
• 32767-18-3 oxygen-18 

Relevant academic research and scientific papers

The four isotopomer reactions of NH(a) and ND(a) with NH3(X) and ND3(X)

The reactions NH(a) + NH3 (X) → products (1) ND(a) + NH3 (X) → products (2) NH(a) + ND3 (X) → products (3) ND(a) + ND3 (X) → products (4) were studied in a quasi-static reaction cell at room temperature and pressures of 10 and 20 mbar with He as the main carrier gas. The electronically excited reactants NH(a) and ND(a) were generated by laser-flash photolysis of HN3 and DN3, respectively, at λ = 308 nm and detected by laser-induced fluorescence (LIF). Also the ground state species NH(X) and ND(X) as products were detected by LIF. From the measured concentration-time profiles of NH(a) and ND(a) under pseudo-first order conditions, the following rate constants were obtained: k1, = (9.1 ± 0.9) × 1013 cm3 mol-1 s-1 k2 = (9.6 ± 1.0) × 1013 cm3 mol-1 s-1 k3 = (8.0 ± 1.0) × 1013 cm3 mol-1 s-1 k4 = (7.2 ± 0.8) × 1013 cm3 mol-1 s-1. The major products are the corresponding NHi-D2-i(X) radicals (i = 0, 1, 2), whereas quenching processes such as NH(a) + ND3 → NH(X) + ND3 are of minor importance (1%). The isotope exchange NH(a) + ND3 → ND(X) + NHD2 is negligible, and the corresponding channel on the singlet surface NH(a) + ND3(X) → ND(a) + NHD2 (X) contributes with 1% to the overall NH(a) depletion in that reaction. The experimental findings are discussed in terms of a chemical activation mechanism by means of statistical rate theory.

Mechanistic Details of the Heterogeneous Decomposition of Ammonia on Platinum

Absolute reaction rates have been measured for the catalytic decomposition of NH3 and ND3 and for the NH3 + D2 exchange reaction over a polycrystalline platinum wire at pressures between 5 x 10-7 and 0.5 torr and temperatures between 400 and 1200 K in a continuous flow microreactor.At relatively low pressures and/or high temperatures, a primary isotope effect was observed for the decomposition of ND3, indicating that a surface reaction involving N-H bond cleavage is the rate-limiting step.Under these conditions, the order of the decomposition reaction is unity with respect to ammonia pressure with an apparent activation energy of 4.2 kcal/mol.A coverages increase, corresponding to relatively high pressures and/or low temperatures, the order of the decomposition reaction is zero with respect to ammonia, and the reaction rate becomes controlled by nitrogen desorption.In this case the apparent activation energy of the decomposition reaction is 22 kcal/mol.The kinetics of the NH3 + D2 exchange reaction have been used, together with data concerning the adsorption-desorption parameters of NH3, H2, and N2 as well as the reaction intermediates NH and NH2, to develop a mechanistic model which descibes the reaction rate over a wide range of experimental conditions and which includes the energetics of each intermediate step in the decomposition reaction.This model is discussed in terms of a potential energy diagram for ammonia decomposition on platinum.