Synthesis of atomic platinum with high loading on metal-organic sulfide

Abstract

Synthesis of ultrafine noble metal with sizes down to nanoscale and even atomic scale is of great significance for heterogeneous catalysis. However, the metal loading is usually kept below 2 wt% due to the aggregation tendency at higher metal contents. Herein, by mimicking the multicentered metal sulfur cluster of metalloenzyme, a bioinspired synthesis of isolated noble metal atoms on the metal-organic sulfide (MOS) framework was reported. The sulfur-rich framework featuring [Mo3S7Br6]2− cluster as the building block and dithiol as the linking node was constructed via chemical bonding and employed to support atomic metal species. Remarkably, highly dispersed platinum atoms with a loading amount as high as 18.5 wt% on the underlying sulfur-rich framework could be obtained after reduction. By increasing the number of benzene rings in the dithiol, the pore size and even the wettability of the MOS frameworks could be modulated. The general applicability of the synthesis could also be extended to the synthesis of atomic Pd. Furthermore, the Pt-loaded MOS could serve as the catalyst for selective hydrogenation of phenylacetylene to styrene in both organic solvent and pure water. Density function theory calculation demonstrated that the atomic Pt sites in the sulfur-rich coordination environment could activate H2 molecules and chemoselectively catalyze the semi-hydrogenation of phenylacetylene to styrene through moderately low energy barriers. The metalation of such a versatile MOS framework will shed light on the synthesis of bioinspired catalytic materials with well-defined structures for more diverse applications.