The conversion o
f polyol materials, including 1,2-diols, into higher commodity chemicals is actively being pursued by many researchers. Here we report the production o
f propanal
from aqueous propylene glycol and hydrogen peroxide using a Ru/alumina catalyst. Experiments were conducted by adding up to
four peroxide equivalents under steady-state re
flux conditions at 371 K. The product propanal and its subsequent reaction product with substrate, 1,3-dioxolane-2-ethyl-4-methyl, was observed to be an intermediate achieving a maximum concentration o
f 3%o
f substrate. Bu
ffering using Mg(OH)
2 at pH
f" alt="not, vert, similar" title="not, vert, similar" border="0"> 10 resulted in propanal
formation, whereas bu
ffering at similar pH using Na
2HPO
4 did not,
from which we propose that magnesium acts as a promoter in the reaction. The mechanism appears to be a dehydration to enol,
followed by rearrangement to product. Experiments utilizing Ru/carbon did not yield any propanol suggesting that the acidic sites o
f alumina aid the dehydration reaction. To our knowledge, this represents the
first time hydrogen peroxide has been used in an alcohol dehydration reaction.