Vapor Phase Photolysis of Formaldehyde at Wavelength 3130A

The vapor phase photolysis of formaldehyde at wavelength 3130A has been investigated at high temperatures. The experimental results indicate that the rate of hydrogen formation is directly proportional to the first power of the intensity of absorbed light, and at constant intensity of absorbed light the rate is accelerated by the addition of formaldehyde or inert gas with about equal efficiency. Propylene and nitric oxide inhibit the rate. The mechanism of the photo-decomposition is suggested to be: H2CO+hν=HCO+HH+H2CO=H2+HCO E≦5 kcalHCO=H+CO E≧13 kcalHCO+(Wall)=Products+(Wall).