Pd Anchored on a Phytic Acid/Thiourea Polymer as a Highly Active and Stable Catalyst for the Reduction of Nitroarene.

A kind of N, P, C, O-containing polymer was easily prepared via microwave heating of phytic acid and thiourea just for 90 s. After impregnation and reduction of H2PdCl4, highly dispersed Pd single atoms/sub-nano clusters loaded on the phytic acid/thiourea polymer (Pd-CNSP) were successfully obtained. Owing to the synergetic effect of the polymer support and Pd, the catalyst Pd-CNSP achieves a great atomic efficiency of Pd species and exhibits an outstanding catalytic ability in the reduction of 4-nitrophenol. The k value of the catalyst Pd-CNSP (2.17 min-1 mg-1) is about 19 times higher than that of the commercial Pd/C (5 wt %) catalyst. The turnover frequency value is as high as 848 min-1, which is the highest value reported so far. Pd-CNSP also has good selectivity for the reduction of halogen-substituted (Cl and Br) nitroaromatics. It is expected to be mass-produced and used in other industrial hydrogenation reactions.