Chemoselective Hydrogenation of Cinnamaldehyde over Pd/CeO2–ZrO2 Catalysts

Abstract

Selective hydrogenation of cinnamaldehyde over Pd (2 wt%) supported on CeO 2, ZrO 2 and CeO 2 -ZrO 2 catalysts is reported for the first time. In general, the olefinic (C=C) group of cinnamaldehyde is preferentially hydrogenated compared to the carbonyl (C=O) group. This selectivity preference could, however, be altered or reversed by adding alkali additives to the catalyst. The influence of additive on the structure and redox properties of the active sites and correlation of that with selective hydrogenation activity is investigated.

Heterogeneous additive‐free highly selective synthesis of 2,5‐bis(hydroxymethyl)furan over catalysts with ultra‐low Pt content

“…At the same time, hydrogen consumption on a bare support in the temperature range from 30 to 250 °C was not detected at all (Fig. 1(a)), confirming the fact that the presence of some metals, including platinum, promotes the reduction of oxide supports under much lower temperatures due to the spillover effect 23–25 . It should be noted that the addition of a zirconium component to CeO 2 not only facilitates its redox cycle in CeO 2 –ZrO 2 mixed oxide, 26 but also can lead to the formation of defects at the interface with cerium oxide, providing additional sites for the activation of the carbonyl group of the substrate 15 …”

Atomically Dispersed Rh Active Sites on Oxide Supports with Controlled Acidity for Gas-Phase Halide-Free Methanol Carbonylation to Acetic Acid

“…This suggested that the inherent reactivity of Rh cluster surfaces, with extended Rh ensembles, for methanol conversion is significantly higher than that of γ-Al 2 O 3 and further that the primary reaction pathway on Rh clusters is methanol decomposition. 56 The addition of 0. The influence of the strength of acidic sites on the oxide support for methanol carbonylation was analyzed by comparing the reactivity of γ-Al 2 O 3 catalysts to ZrO 2 catalysts.…”

“…The addition of 3 wt %Rh to γ-Al 2 O 3 , primarily in the form of Rh clusters, significantly promoted the rate of methanol consumption by ∼10-fold compared to the bare support and switched the selectivity to primarily CO, in addition to CO 2 and DME, see Figure b. This suggested that the inherent reactivity of Rh cluster surfaces, with extended Rh ensembles, for methanol conversion is significantly higher than that of γ-Al 2 O 3 and further that the primary reaction pathway on Rh clusters is methanol decomposition . The addition of 0.2 wt % Rh to γ-Al 2 O 3 resulted in methanol conversion rates and selectivity that were more similar to the bare γ-Al 2 O 3 than observed for the 3 wt % Rh case, see Figure c.…”

Pd/SBA‐15 Catalysts for Hydrogenation of Furfuryl Alcohol to Tetrahydrofurfuryl Alcohol

“…THFOL with high boiling point, miscibility with water and degradable nature made it as a green solvent for industrial applications. THFOL is the starting material for preparation of pentane diols which are used in polymer industry . In addition, THFOL applications are rapidly growing in agricultural formulations for crop sprayers such as pesticides, biocides and also is widely applied in the automotive industry to remove protective coatings, epoxy coatings and paints .…”