Cobalt-Polypyrrole/Melamine-Derived Co-N@NC Catalysts for Efficient Base-Free Formic Acid Dehydrogenation and Formylation of Quinolines through Transfer Hydrogenation

ACS Appl Mater Interfaces. 2020 Jan 8;12(1):474-483. doi: 10.1021/acsami.9b14839. Epub 2019 Dec 17.

Abstract

It is highly desired but remains a great challenge to develop non-noble metal heterogeneous catalysts to supersede noble metal catalysts for formic acid (FA) dehydrogenation and the corresponding transfer hydrogenation reactions. Herein, we developed a simple and feasible melamine-assisted pyrolysis strategy for the preparation of atomic cobalt-nitrogen (Co-N)-anchored mesoporous carbon with high metal loading (>6.8 wt %) and high specific surface area (750 m2 g-1). Systematic investigation reveals that both the organic carbon source polypyrrole and the nitrogen source melamine are crucial for the successful generation of such Co-N-based materials. The obtained samples (Co-N)n@NC were demonstrated to be highly efficient and robust catalysts for FA dehydrogenation and formylation of quinolines through transfer hydrogenation, exhibiting a very high hydrogen production rate of 16 451 mL·gCo-1·h-1 for FA dehydrogenation and affording excellent yields (up to 99%), selectivity (up to 98%), and stability for transfer hydrogenation. This work may provide a promising route for the fabrication of more low-cost metal-nitrogen catalysts for green fine chemical synthesis.

Keywords: base-free; cobalt−nitrogen; dehydrogenation; transfer hydrogenation; transition metal−nitrogen.