Template Guiding for the Encapsulation of Uniformly Subnanometric Platinum Clusters in Beta‐Zeolites Enabling High Catalytic Activity and Stability

Abstract

Subnanometric metal clusters have attracted extensive attention because of their unique properties as heterogeneous catalysts. However, it is challenging to obtain uniformly distributed metal clusters under synthesis and reaction conditions. Herein, we report a template‐guidance protocol to synthesize subnanometric metal clusters uniformly encapsulated in beta‐zeolite, with the metal ions anchored to the internal channels of the zeolite template via electrostatic interactions. Pt metal clusters with a narrow size range of 0.89 to 1.22 nm have been obtained on the intersectional sites of beta‐zeolite (Pt@beta) with a broad range of Si/Al molar ratios (15–200). The uniformly distributed Pt clusters in Pt@H‐beta are subject to strong electron withdrawal by the zeolite, which promotes transfer of active hydrogen, providing excellent activity and stability in hydrodeoxygenation reactions. A general strategy is thus proposed for the encapsulation of subnanometric metal clusters in zeolites with high thermal stability.

Zeolite confinement-catalyzed cleavage of C–O/C–C bonds in biomass

“…Homogeneous encapsulation of Pt in Beta zeolites has been achieved using acetic acid impregnation, tetraethylammonium hydroxide (TEAOH) as a templating agent and PtCl 6− as a metal precursor. 155 Fig. 15c-f confirm the homogeneous encapsulation of Pt in the Beta zeolite.…”

“…OSDAs are essential for the one-pot hydrothermal synthesis of zeolites with ordered structures. Notably, the use of electrostatic interaction between template and metal precursors to stabilize metal ions and localize the metal encapsulation positions has recently been achieved, 155 avoiding the use of organic stabilizers and further achieving more homogeneous and controlled metal encapsulation within the zeolite.…”

“…15 (a and b) Schematic representation of metal@zeolite synthesis using ligand-assisted direct hydrothermal and template-guided methods, respectively. 155 (c-f ) elemental mappings for (c) Al, (d) O, (e) Si and (f ) Pt of Pt@Beta. 155 (g-h) Cs-corrected STEM image of Pt@Beta.…”

“…155 (c-f ) elemental mappings for (c) Al, (d) O, (e) Si and (f ) Pt of Pt@Beta. 155 (g-h) Cs-corrected STEM image of Pt@Beta. 155 (i) schematic representation of metal-encapsulation positions of Pt@Beta.…”

“…155 (g-h) Cs-corrected STEM image of Pt@Beta. 155 (i) schematic representation of metal-encapsulation positions of Pt@Beta. 155 content, which proves the interaction between the cationic PDDA and [Si-O-Al] − (Fig.…”