浸渍法制备尺寸均一可调的贵金属纳米团簇及其尺 寸依赖的催化性质

Abstract

Noble metal nanoclusters, as a bridge between atoms and nanoparticles, show extraordinary catalytic activities because of their unique electronic structures. Such nanoclusters are usually synthesized by a wet chemical approach through unfavorable surface passivation by ligands and have not been obtained by an impregnation approach with satisfactory size uniformity. Herein, we report highly uniform ligand-free noble metal nanoclusters, such as Pd nanoclusters, synthesized each in a silica capsule by an impregnation strategy, with their size accurately engineerable in the range of 0.9-2.9 nm. The key is to ensure the impregnation synthesis with strict control over the nucleation and growth of noble metal nanoclusters by involving hollow silica nanoreactors and non-noble metal competitor ions, thereby showing unprecedented advantages of operational simplicity, scalability, and excellent size controllability. These Pd nanoclusters exhibit a strong size effect on catalysis exemplified by the alcohol oxidation-Knoevenagel condensation sequential reaction, with those of 1.3 nm exhibiting the highest catalytic activity. We believe this novel strategy opens new opportunities for rationally designing efficient noble metal nanocluster-type catalysts for a broad range of important reactions and bringing laboratory-quality nanoclusters into large-scale applications.

Precision Synthesis of Sub-3 nm Bimetallic Alloy Nanoparticles for Efficient and Selective Catalytic Hydrogenolysis of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran

“…Bimetallic alloy nanoparticles often show enhanced catalytic activities in organic synthesis, biomass conversion, and electrocatalysis due to the electronic interplay between their constituent metal components. , The bimetallic components can also collaboratively modulate the configuration of the reactant molecules on the surface of the alloy nanoparticles, leading to desirable catalytic selectivity. − To date, research on bimetallic alloy nanoparticles has primarily focused on larger nanocrystals. − More recently, the forefront of metal catalyst research has shifted to a sub-3 nm size scale. − Within this size range, adding or removing a few metal atoms, i.e., a subtle size change, can result in markedly different catalytic properties, which can be attributed to a significant shift in the d-band center position and the alteration in the population of low-coordination surface sites . Consequently, extraordinary catalytic activities are usually achieved with ultrasmall metal nanoparticles.…”

Engineering Pt nanoclusters on CeO2 surface with abundant point defects by in situ confined-domain encapsulation strategy for the catalytic elimination of VOCs

“…Xue et al 28 explored the combustion mechanism of methane with the help of Pt NCs. Likewise, M NCs, as transitions between nanoparticles and atoms, exhibit a more stable electronic energy band structure than single atoms 29 and have more abundant catalytically active exposure sites than nanoparticles (NPs), which can significantly increase catalytic efficiency. 30,31 Therefore, it is important to expose additional active sites by shrinking Pt species to nanoclusters, thus effectively boosting the catalytic performance.…”

Structural and optical properties of the Ag n –tyrosine complexes ( n = 3−12): a density functional theory study

“…2−3 nm) display quantum confinement effects and properties such as photoluminescence, two-photon absorption and second and third harmonic generation [1]. As a result of these unique features, NMCs are increasingly gaining popularity in optics and catalysis [2][3][4][5]. However, NMCs are usually highly reactive, so it is standard to use capping agents to stabilize them [6].…”