Atomically precise gold nanocluster boosting selective hydrogenation of nitroarene by H2 in water

The chemoselective hydrogenation of molecules containing multiple reducible groups using H2 presents inherent challenges. Here we show a homoleptic nanocluster [Au40(ArC≡C)22](Et4N)2 (Au40 for short, ArC≡C is 3,5-bis(trifluoromethyl)-phenylacetylide) is synthesized in high yield and its structure is elucidated using single-crystal X-ray diffraction. DFT calculations reveals that Au40 features a superatomic 20-electron configuration of (1S)2(1P)6(1D)10(1F)2. Au40/TiO2 exhibits 100% selectivity and activity for the hydrogenation of 4-nitroacetophenone in water, free of base and under mild conditions (80 °C, H2 10 bar). The turnover numbers reach a value of 335,569, and the turnover frequencies 5829 h−1 is an order of magnitude higher than those observed in the well-established Au/TiO2 system. The improved catalytic performance of Au40 is attributed to the synergy of its enhanced durability, unique molecular structure. This work demonstrates that tailoring the surface coordination structure is an effective way to modulate the catalytic performance of cluster catalysts.