Enhanced non-metal catalyzed CO2 reduction on doped biphenylene

- Using non-metals to replace the rare or precious transition metals as active component in catalyst in electrocatalysts is highly desirable in renewable energy applications. The diverse structures of carbon allotropes make it possible to support emerging non-metallic catalysts. Biphenylene is a recently discovered two-dimensional layered carbon allotrope, which outperforms graphene in terms of catalytic activity. Employing density functional theory calculations, we explore the possibility of non-metal doped biphenylene as promising catalyst for CO2 reduction. In aqueous environment, the active sites on the biphenylene surface are partially occupied by H* under reduction potential. On pure biphenylene, the coverage of H* leads to an large onset potential of U > 1.1 V. On boron-doped biphenylene, part of active sites is covered by H*. The remaining unoccupied sites still have activity for CO2 reduction, and the onset potential is significantly reduced to U = 0.2 V. By contrast, nitrogen-doping does not have obvious effect on reducing the onset potential of CO2 reduction (U = 0.9 V). The reason of influencing catalytic activity is then studied. This work reveals provides guidance for the future application of biphenylene in renewable energy.