| Three novel reaction systems were designed and built to examine the partial oxidation of hydrocarbons over noble metal coated monolith and gauze catalysts at contact times {dollar}{dollar}5 atm. The selectivities in all three reactions do not change dramatically with approximately a five fold increase in pressure. This suggests that free radical homogeneous chain reactions are not significant in these three processes and that they can be operated reliably above atmospheric pressure.; Examination of higher alkane oxidation over Pt coated monoliths shows that olefin production is favored, with cracked products resulting from linear and branched hydrocarbons, and cyclic olefins resulting from cyclohexane oxidation. The distribution of products is similar to thermal pyrolysis, but {dollar}beta{dollar}-elimination of H atoms from adsorbed surface species can also explain the distribution of products for the different fuels, and surface reactions explain dehydrogenated products and 1-olefins at high fuel/O{dollar}sb2{dollar} ratios. |
