Issue Date: October 29, 2012
Porosity Promotes Selectivity
A templating process that creates a porous surface layer adds new reactant selectivity to robust metal-oxide catalysts, chemists report (Nat. Chem., DOI: 10.1038/nchem.1477). Supported and bulk oxides catalyze a variety of economically important reactions. Although the oxides may target specific functional groups, they typically can’t discriminate by molecule size, as crystalline microporous materials do. A group led by Northwestern University’s Justin M. Notestein has now developed a way to include size selection by using atomic layer deposition to add a porous film on top of oxide catalyst particles. Notestein and colleagues attached bulky, poorly packed templating ligands to the surface of TiO2 particles. They then added a thin, inert Al2O3 layer that adhered to the TiO2 and surrounded the template molecules. Removing the template molecules left cavities 2 nm wide and 2 nm deep. The researchers used the porous-layer-coated particles to selectively photooxidize benzyl alcohol over 2,4,6-trimethylbenzyl alcohol and reduce nitrobenzene over nitroxylene.
- Chemical & Engineering News
- ISSN 0009-2347
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