▎ 摘　　要

A three-dimensional graphene aerogel-supported Ir (Ir/GA) nanocomposite with interconnected porous framework and high dispersion of Ir nanoparticles is synthesized via a simple yet effective "co-reduction self-assembly" strategy, in which the chemical co-reduction of graphene oxide and H2IrCl6 occurs in the presence of glycerol and Ir is directly incorporated onto the reduced graphene oxide nanosheets. The Ir/GA possesses rich hierarchical porosity, a low amount of oxygen-containing functional groups, and a certain amount of Ir delta- species, which notably improve the accessibility to both sides of the resulting reduced graphene oxide nanosheets, number of active Ir sites, electron transfer ability, and affinity of active Ir with C=O band. As a catalyst in chemoselective cinnamaldehyde (CMA) hydrogenation towards cinnamyl alcohol (CMO), the Ir/GA shows satisfactory CMA conversion of 85.8% and CMO selectivity of 83.2% with a high TOF activity of yielding CMO up to 17.5 h(-1) at reaction time of 1 h. Moreover, the Ir/GA delivers good catalytic durability even after seven successive cycles without pronounced activity deterioration. This study highlights the exciting possibility to synthesize highly efficient graphene-supported precious metal catalysts with multiscale control by overall consideration in mass transportation, metal dispersion, metal-support interactions, and electronic density of active sites for chemoselective CMA hydrogenation.