A General Strategy for Fabricating Isolated Single Metal Atomic Site Catalysts in Y Zeolite

Abstract

Exploring high-performance zeolite-supported metal catalysts is of great significance. Herein, we develop a strategy for fabricating isolated single metal atomic site catalysts in Y zeolite (M-ISAS@Y, M = Pt, Pd, Ru, Rh, Co, Ni, Cu) by in situ separating and confining a metal−ethanediamine complex into β-cages during the crystallization process followed by thermal treatment. The M-ISAS are stabilized by skeletal oxygens of Y zeolite, and the crystallinity, porosity, and large surface area are well inherited in M-ISAS@ Y. As a demonstration, acidic Pt-ISAS@Y is used for n-hexane isomerization involving consecutive catalytic dehydrogenation/hydrogenation on Pt-ISAS and isomerization on Brønsted acid sites. The turnover frequency value of Pt-ISAS reaches 727 h −1 , 5 times more than Pt nanoparticles (∼3.5 nm), with a total isomer selectivity of more than 98%. This strategy provides a convenient route to fabricate promising zeolite-based M-ISAS catalysts for industrial applications.

Zeolite‐Encaged Single‐Atom Rhodium Catalysts: Highly‐Efficient Hydrogen Generation and Shape‐Selective Tandem Hydrogenation of Nitroarenes

“…Very recently, Liu et al. reported a ligand‐protected strategy for preparing isolated metal atoms inside low‐silica Y zeolite via thermal calcination‐reduction processes . However, there remains a lack of facile and generally applicable synthetic methods to fabricate zeolite‐encaged SACs catalysts and until now there is no report for the synthesis of single metal atoms confined within purely siliceous zeolites.…”

Single‐Atom Catalytic Materials for Advanced Battery Systems

“…The spatial confinement strategy, in which single atoms are confined into molecular‐scale cages to avoid the migration, typically includes two steps: 1) using porous materials such as metal–organic frameworks (MOFs), [ 32 ] covalent‐organic frameworks (COFs) [ 31 ] and zeolites, [ 33 ] or self‐assembling minicages or tubes [ 34 ] to trap isolated metal atoms and achieve atomic dispersion; and 2) removing ligands of precursors to obtain single atoms embedded in the skeletons of supports. The porous structure of precursors delivers high conductivity for mass/electron transport and contributes to sufficient exposure of active sites.…”

“…Li's group demonstrated a strategy to fabricated single metal atomic site (M‐ISAS, M = Pt, Pd, Ru, Rh, Co, Ni, Cu) catalysts within Y zeolite (M‐ISAS@Y) by two steps: 1) in situ confining a metal‐ethanediamine (M‐EDA) complex into the β‐cage of Y zeolite through a crystallization process, and 2) anchoring metal atoms within the zeolites by thermal reduction (H 2 flow) (Figure 2d). [ 33 ] The reduction temperatures were 200 °C for Pt, 150 °C for Ru, 300 °C for Cu and Ni, 400 °C for Co, respectively. Typically, on the Pt‐ISAS@NaY sample, the elements of Si, Al and Pt were homogeneously dispersed over the entire Y zeolite (Figure 2e).…”

“…But nanoparticles are usually simultaneously present with single atoms due to bad controllability, indicating that the procedures should be carefully designed. [ 33 ] For example, on substrates with micropores, precursors will probably move and aggregate due to the microporous diffusion limitation. This method is widely applied to achieve spatial confinement, [ 62 ] defect engineering, [ 63,64 ] and coordination designing.…”

Adsorption Behavior and Electron Structure Engineering of Pd-Based Catalysts for Acetylene Hydrochlorination

“…Previous research has proved that cationic Pd species works as catalytic active site in hydrochlorination catalysts [29,30,36]. However, the leaching of Pd active component (in the form of PdCl 2 -C 2 H 2 ) and the reduction of Pd 2+ species during acetylene hydrochlorination reaction has also been widely accepted [36,[62][63][64]. Surprisingly, the addition of ionic liquids and N-containing additives can not only improve the distribution of Pd complex, but also enhance the thermal and chemical stability of Pd species in reaction.…”