Boron-rich crystal porous carbon material as well as preparation method and application thereof

The invention discloses a preparation method and application of a porous carbon material rich in boron crystals, the content of B element in the material can reach 0.5 at%-2.0 at%, the content of O element can reach 20 at%-28 at%, and rich pore structures are distributed in the material. According to the material, citric acid is used as a carbon source, boric acid is used as a boron source, a precursor is prepared after pretreatment, high-temperature annealing is performed, and the porous carbon material rich in boron crystals is prepared. Boron citrate with a layered structure is bound by lamellar boric acid through electrostatic interaction, and the binding of the acting force can induce the formation of nano boron crystals in the high-temperature annealing process. Boric acid serves as a boron source during annealing to provide bonding B atoms for the carbon material, and meanwhile formation of a rich pore structure of the carbon material is promoted. The material can efficiently electrocatalyze a two-elec