ADVERTISEMENT
2 /3 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Materials

Caged Rhodium Makes A Better Catalyst

Catalysis: By encapsulating rhodium nanoparticles in an organic cage, chemists transform a heterogeneous catalyst into a homogenous one

by Bethany Halford
June 8, 2015 | APPEARED IN VOLUME 93, ISSUE 23

[+]Enlarge
Credit: Qiang Xu

Rhodium nanoparticles (purple) are solubilized by placing them in organic cages (C = gray, pink; N = blue).
09323-scicon-1cxd-690.jpg
Credit: Qiang Xu

Rhodium nanoparticles (purple) are solubilized by placing them in organic cages (C = gray, pink; N = blue).

Metal nanoparticles are useful catalysts in many reactions, but keeping them stable in solution over many catalytic cycles has proven challenging. Chemists have taken a number of approaches to the problem, such as using dendrimer supports and metal-organic frameworks to protect the nanoparticles. Using a different tack, researchers in Japan have shown that building a soluble organic cage around rhodium nanoparticles can make the heterogeneous catalysts slip easily into solution, effectively converting them into a homogeneous catalyst (J. Am. Chem. Soc. 2015, DOI: 10.1021/jacs.5b04029). Qiang Xu and his colleagues at Japan’s National Institute of Advanced Industrial Science & Technology created the caged nanoparticles by reducing rhodium acetate in the presence of a porous cyclo - imine cage molecule. The resulting catalyst consists of rhodium nanoparticles about 1 nm across trapped within a cage that has reactant-permeable windows. The caged catalyst is stable and has proved to be superior to all other catalysts in the meth­anolysis of ammonia borane—a reaction that breaks down that hydrogen storage material. And the catalyst can be recovered simply by drying and washing it.

X

Article:

This article has been sent to the following recipient:

Leave A Comment

*Required to comment