Zirconia-Supported Ruthenium Catalyst for Efficient Aerobic Oxidation of Alcohols to Aldehydes

Abstract

We have developed the supported ruthenium catalyst (Ru(OH) x /ZrO 2 ) that shows highly efficient catalytic performance for the oxidation of activated, nonactivated, and heterocyclic alcohols with only 1 atm of molecular oxygen as a green oxidant. The ruthenium active site gave excellent aerobic alcohol oxidation reaction (turnover number (TON) = 63 000). The catalyst was easily recovered after the reaction and could be reused without a significant loss of its catalytic performance.

Influence of Sulfuric Acid on the Performance of Ruthenium‐based Catalysts in the Liquid‐Phase Hydrogenation of Levulinic Acid to γ‐Valerolactone

“…Figure b shows that the bare (monoclinic) ZrO 2 support exhibits some surface acidity, with a total amount of acid sites of 0.25 mmol g −1 , in agreement with literature values . Impregnation of Ru on ZrO 2 had a pronounced effect on acidity as the fresh Ru/ZrO 2 catalyst showed an intense desorption peak that increased the total amount of acid sites to 0.43 mmol g −1 , which was attributed to various amounts of Lewis‐acidic Ru centers and/or generation of oxygen‐deficient sites . Compared to the fresh Ru/ZrO 2 catalyst, a noticeable increase of the intensity of the broad peak in the TPD‐NH 3 profile in the range of 373–515 K was observed for the spent Ru/ZrO 2 material (after reaction with 0.5 wt % H 2 SO 4 and acetone wash), suggesting an increase in the amount of weak acid sites exclusive to ZrO 2 .…”

Prefunctionalized Porous Organic Polymers: Effective Supports of Surface Palladium Nanoparticles for the Enhancement of Catalytic Performances in Dehalogenation

“…[12][13][14] In contrast, metal NPs on the external surface can provide higherc atalytic activity than NPs in the interior cavities,o wing to acceleration of mass transfer and easy availability of active sites. [15][16][17][18] However,t hese surface metal NPs have received little attention because they are instable and prone to aggregation. It is desirable but challenging to seek for an effective strategy to immobilize metal NPs on the externalsurfaceofporous materials.…”

Supported Porous Nanomaterials as Efficient Heterogeneous Catalysts for CO2 Fixation Reactions

“…[147] Due to the availability of more active sites and accelerated mass transfer,m etal nanoparticles on the outer surfaces hows faster catalytic activity than those on the inner surface. [148] For as mall nanoparticles, av ery large fraction of metal/metalo xide atom/molecules are exposed at the surface and this largely enhances the catalytic activity over its bulk counterpart. The surface metal NPs are known for their proneness to aggregation and instability.T herefore, immobilization of metal NPs on the exteriors urfaceo ft he porous nanomaterials is not desirable.…”