In-situ generated highly dispersed nickel nanoclusters confined in MgAl mixed metal oxide platelets for benzoic acid hydrogenation

Abstract A new and cost-effective NiMgAl mixed metal oxide (Ni 2 Mg 0.5 Al 1 -MMO) catalyst derived from hierarchical flower-like Ni-Mg-Al layered double hydroxides (NiMgAl-LDHs) was fabricated by a hydrothermal-calcination-reduction method. This catalyst showed excellent catalytic performance in the selective hydrogenation of benzoic acid to cyclohexanecarboxylic acid. Notably, recycling experiments demonstrated that this catalyst could be used at least ten times without significant losses in activity and selectivity under harsh reaction conditions; thus, it presents similar behavior to most of noble metal catalysts. A series of characterizations were performed to investigate the relationship between the structure and the catalytic performance of this catalyst and elucidate the mechanism of its good stability. The results demonstrated that the Ni 2 Mg 0.5 Al 1 -MMO catalyst exhibited highly dispersed nickel species due to the well-defined flower-like structure of NiMgAl-MMO platelets as well as the confined effect of Mg and Al oxide species.