ISSN:
1572-8986
Keywords:
Plasma synthesis
;
ammonia
;
catalysis
;
wall effect
;
nitrogen-hydrogen reaction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Technology
Notes:
Abstract The plasma synthesis of ammonia was stuided at pressures of 1–5 torr and flow rates of up to 200 torr cm3 min−1 using Pyrex and silver surfaces cooled to 77 K. The N conversion to ammonia was about 13% in experiments in which the afterglow was trapped on the Pyrex surface. By quenching the plasma rather than the afterglow, the percent N conversion could be doubled using the Pyrex surface and quadrupled using the silver surface. Increasing the hydrogen pressure and/or hydrogen discharge cleaning decreased the percent N conversion; nitrogen discharge conditioning had no significant effect. With increasing nitrogen flow rate the percent N conversion decreased linearly in the quenched plasma reaction on the silver surface, suggesting nitriding and reduction by hydrogen to form ammonia. The exponential decrease of the percent N conversion in the quenched afterglow reaction on the Pyrex surface is explained by the formation and/or dissociation of adsorbed N2 determining the ammonia yield at 77 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01016001
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