A Heterogeneous Metal‐Free Catalyst for Hydrogenation: Lewis Acid–Base Pairs Integrated into a Carbon Lattice

• Published in: Angewandte Chemie International Edition 2018-10, Vol.57 (42), p.13800-13804
• Main Authors: Ding, Yuxiao, Huang, Xing, Yi, Xianfeng, Qiao, Yunxiang, Sun, Xiaoyan, Zheng, Anmin, Su, Dang Sheng
• Format: Article
• Language: English
• Subjects: Acidity; Base pairs; Basicity; Boron; Carbon; Catalysis; Catalysts; Diamonds; Electrons; Graphitic structure; heterogeneous catalysis; Hydrogenation; Lewis acid; Lewis pairs; metal-free catalysis; Metals; nanocarbons; Nanostructure; Substrates
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201803977

Designing heterogeneous metal‐free catalysts for hydrogenation is a long‐standing challenge in catalysis. Nanodiamond‐based carbon materials were prepared that are surface‐doped with electron‐rich nitrogen and electron‐deficient boron. The two heteroatoms are directly bonded to each other to form unquenched Lewis pairs with infinite π‐electron donation from the surrounding graphitic structure. Remarkably, these Lewis pairs can split H2 to form H+/H− pairs, which subsequently serve as the active species for hydrogenation of different substrates. This unprecedented finding sheds light on the uptake of H2 across carbon‐based materials and suggests that dual Lewis acidity–basicity on the carbon surface may be used to heterogeneously activate a variety of small molecules. Lewis in the sky with diamonds: Solid‐phase metal‐free Lewis pairs, comprised of electron‐rich nitrogen and electron‐deficient boron, were dispersed on sp2‐hybridized diamond surfaces. The unquenched Lewis pairs split H2 into H+ and H− and can be used to catalytically hydrogenate a range of substrates.