Until now, it has been believed that Brønsted acid sites in amorphous silica-alumina are formed from only tetra-coordinated (AlIV) sites. Here, the authors use 27Al-{1H} correlation NMR experiments to identify a new AlV-based Brønsted acid site, with implications for increasing the acidity of solid acid catalysts.
- Zichun Wang
- Yijiao Jiang
- Jun Huang