Hydrotalcite-based CoxNiyAl1Ox mixed oxide as a highly efficient catalyst for selective ethylbenzene oxidation

Abstract

• Co-Ni-Al layered double hydroxide was prepared via a simple coprecipitation method. • After calcination, the CoNiAlO mixed oxide with nanosheet structure was obtained. • The catalyst exhibits high efficiency in the selective oxidation of ethylbenzene. • It is attributed to the interactions between Co-Ni species and special structure. In this study, a series of Co–Ni–Al–layered double hydroxides (Co x Ni y Al 1 –LDHs) was successfully prepared via a simple co-precipitation method with Na 2 CO 3 and NaOH as the precipitants. After the calcination of the Co x Ni y Al 1 –LDH precursors, the Co–Ni–Al–O mixed oxides were formed and used as highly efficient catalysts in the selective oxidation of ethylbenzene to acetophenone. The Ni addition to CoAlO x can induce the formation of interactions between Co–Ni species and affect the dispersion of metal active centers, thereby greatly influencing the catalytic performance. The typical Co 2 Ni 1 Al 1 O x sample with a Co:Ni molar ratio of 2:1 exhibited the highest surface area (165 m 2 /g) and the best catalytic performance (80.0% ethylbenzene conversion and 88.9% acetophenone selectivity). The high catalytic efficiency was mainly attributed to the high-efficiency synergistic effect between the highly dispersed active center Co and the promoter Ni species. More importantly, the good recyclability and stability of the Co 2 Ni 1 Al 1 O x catalyst made it more competitive. A Co 2 Ni 1 Al 1 O x mixed oxide catalyst was obtained from the Co-Ni-Al layered double hydroxide precursor, which exhibited the high catalytic performance in the selective oxidation of ethylbenzene to acetophenone.