2024-02-16 ハーバード大学
◆アイゼンバーグ教授らは、高度に整然とした多孔質材料を設計し、新しい触媒プラットフォームを開発した。このプラットフォームでは、一部のナノ粒子が基板に埋め込まれ、他の部分が露出して触媒反応を効率的に行うことができる。
◆研究では、ナノ粒子間の距離が反応の選択性に大きな影響を与えることが明らかにされた。これにより、より有用な中間体や最終生成物を選択的に生成する触媒プラットフォームが可能になり、化学プロセスの最適化やエネルギー消費の削減に役立つことが期待される。
＜関連情報＞
- https://seas.harvard.edu/news/2024/02/towards-more-efficient-catalysts
- https://www.nature.com/articles/s41929-023-01104-1
ナノ粒子の近接性がベンズアルデヒド水素化反応の選択性を制御する Nanoparticle proximity controls selectivity in benzaldehyde hydrogenation
Kang Rui Garrick Lim,Selina K. Kaiser,Haichao Wu,Sadhya Garg,Marta Perxés Perich,Jessi E. S. van der Hoeven,Michael Aizenberg & Joanna Aizenberg
Nature Catalysis Published:16 February 2024
DOI:https://doi.org/10.1038/s41929-023-01104-1
Abstract
Disentangling the effects of nanoparticle proximity and size on thermal catalytic performance is challenging with traditional synthetic methods. Here we adapt a modular raspberry-colloid-templating approach to tune the average interparticle distance of PdAu alloy nanoparticles, while preserving all other physicochemical characteristics, including nanoparticle size. By controlling the metal loading and placement of pre-formed nanoparticles within a 3D macroporous SiO2 support and using the hydrogenation of benzaldehyde to benzyl alcohol and toluene as the probe reaction, we report that increasing the interparticle distance (from 12 to 21 nm) substantially enhances selectivity towards benzyl alcohol (from 54% to 99%) without compromising catalytic performance. Combining electron tomography, kinetic evaluation and simulations, we show that interparticle distance modulates the local benzyl alcohol concentration profile between active sites, consequently affecting benzyl alcohol readsorption, which promotes hydrogenolysis to toluene. Our results illustrate the relevance of proximity effects as a mesoscale tool to control the adsorption of intermediates and, hence, catalytic performance.
