Boosting the catalysis of gold by O2 activation at Au-SiO2 interface

Abstract

Supported gold (Au) nanocatalysts have attracted extensive interests in the past decades because of their unique catalytic properties for a number of key chemical reactions, especially in (selective) oxidations. The activation of O 2 on Au nanocatalysts is crucial and remains a challenge because only small Au nanoparticles (NPs) can effectively activate O 2 . This severely limits their practical application because Au NPs inevitably sinter into larger ones during reaction due to their low Taman temperature. Here we construct a Au-SiO 2 interface by depositing thin SiO 2 layer onto Au/TiO 2 and calcination at high temperatures and demonstrate that the interface can be not only highly sintering resistant but also extremely active for O 2 activation. This work provides insights into the catalysis of Au nanocatalysts and paves a way for the design and development of highly active supported Au catalysts with excellent thermal stability.

Electronic Oxide–Metal Strong Interaction (EOMSI)

“…Meanwhile, novel OMI effects were also reported, likely owing to the different preparation methods of inverse powder catalysts from those of inverse model catalysts. Al 2 O 3 overlayers on Pd nanocrystals prepared by atomic layer deposition exhibited abundant penta‐coordinated Al 3+ cations, [42] and charge transfer occurs from Au nanoparticles to the supported SiO 2 adlayers prepared by wet chemistry deposition [43] …”

“…Recently, with successful depositions of oxide adlayers on supported or unsupported metal particles, oxide/metal inverse powder catalysts have emerged as a novel type of efficient catalysts with oxide–metal interfaces as the active sites [39–43] . OMI effects on the structures of the oxide adlayers in powder inverse catalysts similar to those in the corresponding model inverse catalysts were observed.…”

Recent Advances in Catalytic Confinement Effect within Micro/Meso‐Porous Crystalline Materials

“…The single-site Pt species isolated by organic linkers, exhibited great stability and sintering resistance up to 200 °C. Then Pt species showed a uniform dispersion in NU-1000, while maintaining the structural integrity during the 8 (μ 2 -OH) 6 nodes, respectively; g) Hydrogenation conversion of nitroarene, nitrile, and isocyanide compounds with different SBU supported Co-H catalysts. Reproduced with permission.…”

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Among them, great efforts have been made to elucidate the correlations between the reaction performance and the specific physical properties of the catalyst. During this period, some secondary concepts were introduced and widely discussed such as strong metal-support interaction (SMSI), [8][9][10][11][12] hydrogen spillover, [13,14] and the confinement effect, [15][16][17][18] etc.The "confinement effect" is a vital factor affecting the reaction, focusing prominently on porous materials. It mainly includes the physical constraint effect, [19,20] the electronic effect, [21] and the molecular enrichment effect.

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“…Among them, great efforts have been made to elucidate the correlations between the reaction performance and the specific physical properties of the catalyst. During this period, some secondary concepts were introduced and widely discussed such as strong metal-support interaction (SMSI), [8][9][10][11][12] hydrogen spillover, [13,14] and the confinement effect, [15][16][17][18] etc.…”