Graphene‐Supported Ultrafine Metal Nanoparticles Encapsulated by Mesoporous Silica: Robust Catalysts for Oxidation and Reduction Reactions

Abstract

Graphene nanosheet-supported ultrafine metal nanoparticles encapsulated by thin mesoporous SiO2 layers were prepared and used as robust catalysts with high catalytic activity and excellent high-temperature stability. The catalysts can be recycled and reused in many gas- and solution-phase reactions, and their high catalytic activity can be fully recovered by high-temperature regeneration, should they be deactivated by feedstock poisoning. In addition to the large surface area provided by the graphene support, the enhanced catalytic performance is also attributed to the mesoporous SiO2 layers, which not only stabilize the ultrafine metal nanoparticles, but also prevent the aggregation of the graphene nanosheets. The synthetic strategy can be extended to other metals, such as Pd and Ru, for preparing robust catalysts for various reactions.

Heterogeneous Catalyst Deactivation and Regeneration: A Review

“…Both the Al2O3 layer and catalyst layer 2 protect the sulfur-sensitive components of catalyst layer 1 from poisoning by SO2.. Often, ideal metal dispersions require metal nanoparticles to be distributed closely together, but these particles are thermodynamically unstable on the surface and undergo rapid sintering, as described in Section 2.3 above. Recently, in an attempt to reduce sintering rates, researchers have attempted to stabilize the metal nanoparticles by first dispersing them on a support, encapsulating them in the same or another metal oxide, and then opening porosity to the particles (e.g., [247,248]). These approaches have met with varying degrees of success, but point to promising new areas of synthesis techniques that have the potential to reduce or to eliminate deactivation by sintering.…”

Polyimide/mesoporous silica nanocomposites: Characterization of mechanical and thermal properties and tribochemistry in dry sliding condition

“…Thus, excellent mechanical, thermal and tribological properties of PI-based composites are essentially needed to endure heavy load or elevated temperature. Mesoporous molecular sieves have attracted much attention since their first discovery [2][3][4][5]. Mesoporous materials benefit from two advantages including extremely high specific surface area (normally >500m 2 /g) and interconnected mesoporous structures.…”

A novel Bi-based oxybromide SrBiO2Br: Synthesis, optical property and photocatalytic activity

“…During the past decades, semiconductor photocatalytic materials have attracted much interest in environment decontamination and clean hydrogen energy production [1][2][3][4][5]. Titanium dioxide (TiO 2 ) has been proved to be the most promising materials for its superior photocatalytic performance, nontoxicity, low cost and long-term stability and chemical corrosion [6,7].…”