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.
Similar content being viewed by others
References
K. S. Yin and M. Venugopalan,Plasma Chem. Plasma Process. 3, 343 (1983).
G. Y. Botchway and M. Venugopalan,Z. Phys. Chem. Neue Folge 120, 103 (1980).
J. Kalman, T. A. Varga, and R. Hajos,Proc. Sixth Int. Symp. Plasma Chem., Montreal, 1983, p. 686.
M. Venugopalan and S. Veprek, inPlasma Chemistry IV (Topics in Current Chemistry, No. 107), Springer-Verlag, Berlin (1983).
M. Venugopalan, G. Y. Botchway, and R. F. Suda,Proc. Fifth Int. Symp. Plasma Chem., Edinburgh, 1981, p. 694.
K. Yin, R. F. Suda, G. Y. Botchway, and M. Venugopalan,Proc. Seventh Int. Symp. Plasma Chem., Eindhoven, 1985, p. 309.
K. Sugiyama, K. Akazawa, M. Oshima, H. Miura, T. Matsuda, and D. Nomura,Plasma Chem. Plasma Process. 6, 179 (1986).
J. E. Nicholas, A. I. Spiers, and N. A. Martin,Plasma Chem. Plasma Process. 6, 39 (1986).
C. Braganza, S. Veprek, E. Wirz, H. Stuessi, and M. Textor,Proc. Fourth Int. Symp. Plasma Chem., Zurich, 1979, p. 100.
M. Venugopalan and R. Avni, inThin Films from Free Atoms and Particles, K. J. Klabunde, ed., Academic Press, Orlando (1985), pp. 113–116.
F. Cramarossa, G. Ferraro, and E. Molinari,J. Quant. Spectrosc. Radiat. Transfer 14, 419 (1973).
R. d'Agostino, F. Cramarossa, S. de Benedictis, and G. Ferraro,Plasma Chem. Plasma Process. 1, 19 (1981).
D. Rapakoulias, J. Amouroux, M. P. Bergougnan, and A. Gicquel,Rev. Phys. Appl. 17, 95 (1982).
M. P. Bergougnan, A. Gicquel, and J. Amouroux,Rev. Phys. Appl. 18, 335 (1983).
A. Gicquel, M. P. Bergougnan, and J. Amouroux,Proc. Electrochem. Soc. 83 (10), 169 (1983).
J. Amouroux, A. Gicquel, S. Cavvadias, D. Morvan, and F. Arefi,Pure Appl. Chem. 57, 1210 (1985).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Touvelle, M., Licea, J.L.M. & Venugopalan, M. Plasma chemical synthesis. II. Effect of wall surface on the synthesis of ammonia. Plasma Chem Plasma Process 7, 101–108 (1987). https://doi.org/10.1007/BF01016001
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01016001