Cage effects control the mechanism of methane hydroxylation in zeolites

Fencing in radicals Zeolite catalysis could potentially offer a more direct route from methane to methanol. However, current catalysts tend to deactivate too quickly for practical use. Snyder et al. investigated the deactivation mechanism using Mössbauer and Raman spectroscopy and accompanying simulations (see the Perspective by Scott). Their results suggest that in zeolites with large apertures, after iron active sites strip hydrogen from methane, the resulting methyl radicals can leak away and deactivate other iron centers. Zeolites with tighter apertures can keep the radicals nearby longer, favoring the formation of methanol. Science , abd5803, this issue p. 327 ; see also abj4734, p. 277