Photocatalytic CH-to-Ethanol Conversion on Asymmetric Multishelled Interfaces.

The selective oxidation of methane (CH) features attractive potentials in both mitigating global warming and producing value-added chemicals. However, due to the short-life and unpaired concentrations of reactive intermediates (such as ·OH, ·CH, and CO), the selective formation of multicarbon products like ethanol has remained challenging. In this work, we developed a hollow multishelled CeO@PdO@FeO nanosphere catalyst with two asymmetric and closely connected interfaces, featuring efficient in-tandem photo-oxidation of CH into ethanol with O as the oxidant. The outer FeO surface promotes the photoreduction of the oxazole atoms in O. In the meantime, the two asymmetric PdO/FeO and CeO/PdO catalytic interfaces enable selective photoactivation of CH to ·CH and then to CO, respectively, and the hollow multishelled structure further facilitates the directional transport and coupling of the as-generated ·CH and CO to produce ethanol. Under 100 mW·cm light intensity and ambient conditions, the hollow multishelled CeO@PdO@FeO nanosphere photocatalyst exhibited a peak CH-to-ethanol yield of 728 μmol·g·h without photosensitizers or sacrificial agents, almost three times higher than the previous best reports on photocatalytic CH oxidation to ethanol, suggesting the attractive potential of the asymmetric multishelled catalytic interfaces.