Ni foams decorated with carbon nanotubes as catalytic stirrers for aerobic oxidation of cumene

Abstract

Carbon nanotubes (CNTs) have received intensive scientific interests as a metal-free catalyst for the oxidation reactions of hydrocarbons in the liquid phase. However, its application in the liquid reaction is limited by the costly catalyst filtration process. Herein, a structured CNT catalyst was fabricated via growing CNTs on Ni foams with a porous Al2O3 coating layer. The resultant structured CNTs were used both as catalysts and as stirrer in a rotating foam stirrer reactor. The catalytic performance was evaluated in the production of cumene hydroperoxide by the aerobic oxidation of cumene. Under optimized experimental conditions, the cumene conversion reached 25.1%, 14% higher than that of commercial CNTs in a slurry reactor. The excellent adhesion strength of CNTs on the foam and catalytic stability in 5 runs of recycling were demonstrated, opening a new way to employing CNTs as a metal-free catalyst in the liquid phase reactions.