Hot bubbles
15 Jan 2000
Ultrasound technology has enabled researchers at the University of Illinois to make catalysts for the desulphurisation of oil. The molybdenum-based catalysts can remove sulphur ten times faster than existing technologies.
In an article in the Journal of the American Chemical Society, Kenneth Suslick describes how he used molybdenum disulphide (MoS2) as a starting point. This occurs in sheet-like crystals which are poor catalysts.
However, the researchers found that applying ultrasound to a solution of MoS2 generates a plethora of tiny bubbles which implode, generating temperatures in excess of 5000 degrees C and pressures of some 1000atm. As the bubbles cool, they form nanometre-sized particles of MoS2, which are highly efficient catalysts.
