Nitrogen and boron atoms are doped onto the nanocarbon surface to construct an efficient heterogeneous metal-free catalyst. This catalyst, activate CO₂ effectively, reducing it to CO with silane through a thermal route. This unprecedented finding sheds light on the application of heterogeneous metal-free carbon materials in thermal CO₂ transformation.

Due to high thermal stability, the selective cleavage of the CO bond in CO₂, catalyzed by heterogeneous catalysts, is quite challenging, especially in thermal catalytic areas. For the first time, metal-free active sites for thermal CO₂ activation and transformation are constructed on the nanocarbon surface in this work. The potential H-assisted cleavage of the activated CO bond to produce CO on the metal-free catalyst is predicted and further confirmed by its reduction using silane as a hydrogen resource. With in situ infrared spectroscopy and theoretical calculations, the evolution process of CO₂ on the surficial N, B heteroatomic sites of the nanocarbon, providing valuable insights into the reaction mechanism of CO₂ transformation is revealed. This unprecedented finding not only enhances the understanding of the metal-free catalytic process for the selective cleavage of the CO bond in CO₂ but also provides more opportunities for designing high-efficiency, low-cost, and scalable heterogeneous carbon-based catalysts in thermal CO₂ transformation processes.