Green, Multi‐Gram One‐Step Synthesis of Core–Shell Nanocomposites in Water and Their Catalytic Application to Chemoselective Hydrogenations

Abstract

We devise a new and green route for the multi-gram synthesis of core-shell nanoparticles (NPs) in one step under organic-free and pH-neutral conditions. Simply mixing core and shell metal precursors in the presence of solid metal oxides in water allowed for the facile fabrication of small CeO -covered Au and Ag nanoparticles dispersed on metal oxides in one step. The CeO -covered Au nanoparticles acted as a highly efficient and reusable catalyst for a series of chemoselective hydrogenations, while retaining C=C bonds in diverse substrates. Consequently, higher environmental compatibility and more efficient energy savings were achieved across the entire process, including catalyst preparation, reaction, separation, and reuse.

Heterolytic cleavage of dihydrogen (HCD) in metal nanoparticle catalysis

“…The same nanomaterial but supported on hydrotalcite (Au@CeO 2 /HT) exhibits also a high selectivity in the hydrogenation of unsaturated aldehydes and ketones towards the corresponding unsaturated alcohols. 128 A similar selectivity due the above-mentioned H 2 heterolytic cleavage was observed by the same group using the analogous silver material (Ag@CeO 2 ) supported on ceria. 129 High levels of chemoselectivity in the hydrogenation of substituted nitroaromatics were also observed by Shimizu et al by using Au/Al 2 O 3 as a catalyst.…”

Zinc‐Mediated Efficient and Selective Reduction of Carbonyl Compounds

“…(Cyclohex‐3‐en‐1‐yl)methanol (2a 36 ): According to GP‐I, 3‐cyclohexenecarbaldehyde ( 1a 35 ) (110 mg, 1.0 mmol, 1.0 equiv.) afforded 2a 36 (88 mg, 78 %) as a colorless liquid.…”

A Titanium Dioxide Supported Gold Nanoparticle Catalyst for the Selective N‐Formylation of Functionalized Amines with Carbon Dioxide and Hydrogen

“…In addition, Au/TiO 2 was shown to hydrogenate substituted nitroaromatics selectively to the corresponding anilines . Our own group also reported that Au NPs supported on hydrotalcite (Au/HT) and CeO 2 ‐encapsulated Au NPs (Au@CeO 2 ) promoted the highly chemoselective hydrogenation of epoxides and alkynes to the corresponding alkenes ,,…”