Nanoceria as a recyclable catalyst/support for the cyanosilylation of ketones and alcohol oxidation in cascade

Ceria-Based Materials for Thermocatalytic and Photocatalytic Organic Synthesis

“…Deori et al reported that after the surface modification by oleic-acid, (100) surface-exposing CeO 2 nanocubes can perform as an efficient catalyst for the selective oxidation of benzyl alcohol and para-chlorobenzyl alcohol to the corresponding aldehydes with absolute selectivity (>99%) in water at 35 °C under 1 bar oxygen pressure. 55 The exposed (100) surfaces with high oxygen vacancy concentrations on CeO 2 nanocubes are assumed to favor the adsorption of molecular oxygen and the cleavage of the O−H bond of the alcohol, resulting in the conversion of alkoxide species and the adsorbed oxygen species to the aldehyde. The hydrophobic oleic acid contributed to the high catalytic activity by forming substrate diffusion channels toward the active surface of the ceria, as compared with the very low conversion and selectivity over the annealed as-synthesized ceria nanocubes and CeO 2 nanospheres without the addition of oleic acid.…”

“…As demonstrated by experimental results and theoretical calculations, CeO 2 nanomaterials (e.g., nanocubes, nanooctahedra, and nanorods) with different exposure of crystal planes have different oxygen vacancy formation energies. Following this consideration, Wang et al investigated the effects of the exposed crystal planes in CeO 2 catalysts on the formation of imines via the oxidative coupling of alcohols and amines and found that among the (110), (100), and (111) planes, the (110) plane exhibits the best catalytic activity (i.e., a 97% yield of the imine) because of its lowest oxygen vacancy formation energy, the highest oxygen vacancy concentration, and the strongest redox performance, as summarized in Figure 4b. 58 The DFT results indicated that the nucleophilic attack of lattice oxygen is the rate-determining step in the alcoholysis of amides on the surface of CeO 2 .…”

“…11,13 For example, nanooctahedra with exposure of (111) and (100) crystal planes, nanorods with exposure of ( 110) and (100) crystal planes, and nanocubes with exposure of (100) crystal plane can be prepared via a facile hydrothermal method. 11 Generally, three typical lowindex lattice planes (i.e., (100), (110) and (111)) exist on the surface of CeO 2 nanocrystals, as shown in Figure 2. 14 Based on theoretical studies and experimental results, the oxygen vacancy formation energy for different surface facets of ceria nanocrystals follows the order of ( 110) < (100) < (111).…”

“…14 Based on theoretical studies and experimental results, the oxygen vacancy formation energy for different surface facets of ceria nanocrystals follows the order of ( 110) < (100) < (111). 15,16 However, the CeO 2 (100) facet with bipolarity and low coordinative saturation would lead to lability of surface ions and neighboring ions, resulting in better activity and higher oxygen storage capacity (OSC) following the sequence (111) < ( 110) < (100). 15 Therefore, pure CeO 2 nanocrystals exposing different facets usually result in different catalytic activity.…”

Controlling Multiple Active Sites on Pd−CeO2 for Sequential C−C Cross‐coupling and Alcohol Oxidation in One Reaction System

“…However, a design strategy using the active sites together to perform consecutive catalytic reactions in one reaction system has rarely been studied. [32] To expand the potential of CeO 2 -supported metal catalysts for more complicated and advantageous multistep reactions, it is necessary to explore rational design strategies for CeO 2 -based catalysts by controlling catalytic functions on their surface.…”