Ultraviolet-gas phase and -photocatalytic synthesis from CO and NH3

Abstract

Photocatalytic syntheses of¹⁴C-urea, -formamide, and -formaldehyde are effected by irradiation of¹⁴CO and NH₃ in the presence of Vycor, silica gel, or volcanic ash shale surfaces. These syntheses are catalyzed by ultraviolet wavelengths longer than those absorbed by the gaseous reactants. The syntheses are also effected when the surface material is first irradiated in the presence of CO followed by a dark incubation with NH₃. Apparently, the initiating step is a light dependent formation of a reactive form of CO on the surface. A discussion is given on the possible contribution of these reactions to the abiotic synthesis of organic nitrogen compounds on Mars, on the primitive Earth and in interstellar space.