Highly Efficient Hybrid Cobalt–Copper–Aluminum Layered Double Hydroxide/Graphene Nanocomposites as Catalysts for the Oxidation of Alkylaromatics

Abstract The selective oxidation of alkylaromatics is of vital importance for the production of high‐added‐value raw materials. The development of highly efficient heterogeneous catalytic oxidation systems under mild conditions has become an attractive research area. In this work, hybrid Co–Cu–Al layered double hydroxide/graphene (CoCuAl‐LDH/graphene) nanocomposites, which were assembled successfully by a one‐step coprecipitation route without the use of any additional reducing agents, were used as highly efficient catalysts for the liquid‐phase selective oxidation of ethylbenzene using tert ‐butyl hydroperoxide as the oxidant. A series of characterizations revealed that graphene could stabilize CoCuAl‐LDH nanoplatelets effectively in the nanocomposites, and in turn, highly dispersed CoCuAl‐LDH could prevent the aggregation of the graphene nanosheets. By fine‐tuning the mass ratio of graphene to CoCuAl‐LDH, such nanocomposites offered a tunable catalytic oxidation performance. In particular, the nanocomposite with the graphene/CoCuAl‐LDH mass ratio of 0.4:1 exhibited a remarkable catalytic performance with a considerable conversion (96.8 %) and selectivity to acetophenone (>95.0 %), which was mainly attributed to the synergism between the active CoCuAl‐LDH component and the graphene matrix in the unique hetero‐nanostructure. Moreover, the as‐assembled nanocomposite catalysts displayed good recyclability and were active for the selective oxidation of other alkylaromatics.