Synthesis of Fully Exposed Single-Atom-Layer Metal Clusters on 2D Ordered Mesoporous TiO2 Nanosheets

Abstract

A sulfhydryl monomicelles interfacial assembly strategy is presented for the synthesis of fully exposed single-atom-layer Pt clusters on 2D mesoporous TiO₂ (SAL-Pt@mTiO₂ ) nanosheets. This synthesis features the introduction of the sulfhydryl group in monomicelles to finely realize the controllable co-assembly process of Pt precursors within ordered mesostructures. The resultant SAL-Pt@mTiO₂ shows uniform SAL Pt clusters (≈1.2 nm) anchored in ultrathin 2D nanosheets (≈7 nm) with a high surface area (139 m² g^-1 ), a large pore size (≈25 nm) and a high dispersion (≈99 %). Moreover, this strategy is universal for the synthesis of other SAL metal clusters (Pd and Au) on 2D mTiO₂ with high exposure and accessibility. When used as a catalyst for hydrogenation of 4-nitrostyrene, the SAL-Pt@mTiO₂ shows a high catalytic activity (TOF up to 2424 h^-1 ), 100 % selectivity for 4-aminostyrene, good stability, and anti-resistance to thiourea poisoning under relatively mild conditions (25 °C, 10 bar).

Keywords: Mesoporous Materials; Metal Clusters; Selective Hydrogenation; Single-Atom-Layer; Two-Dimensional.