Three-Dimensional Porous Hexagonal Boron Nitride Fibers as Metal-Free Catalysts with Enhanced Catalytic Activity for Oxidative Dehydrogenation of Propane

Abstract

Boron nitride (BN) as an emerging and revolutionary metal-free catalyst has demonstrated great potential in various oxidative dehydrogenation reactions. However, traditional BN sheets always present low catalytic performance because of the lack of exposed surface-active sites. In this work, we synthesized a three-dimensional (3D) porous fiber-like BN material via self-assembly of boric acid and melamine. In the catalytic oxidative dehydrogenation of propane (ODHP), the as-synthesized BN showed remarkable selectivity to propylene (76.4%), and the selectivity to alkenes was above 90% at a 16.4% conversion of propane, while the selectivity to undesired CO2 was negligible. Meanwhile, the 3D BN also exhibited excellent catalytic stability up to 200 h at 520 °C, which was much better than traditional BN sheets. Mechanistic insight into the formation process of 3D porous BN fibers suggests the key role of surface BO X affiliated to BN for stable 3D structure in contributing to the high catalytic activity and outstanding stability. This work is, therefore, a blueprint for the construction of the next-generation BN catalyst for a highly efficient ODHP.

Catalyst development for O2-assisted oxidative dehydrogenation of propane to propylene

“…For example, it has been revealed that doping a small amount of C into BN could enhance the incorporation of O atoms into the BN lattice, leading to the generation of more active species for O 2 -ODHP. 124 However, if an excessive amount of C was doped into BN, the catalyst would suffer from decomposition and sintering severely, which consequently could result in a decrease in catalytic activity. Therefore, the valence of foreign elements doped into BN should be well regulated.…”

Advanced design and development of catalysts in propane dehydrogenation

“…For instance, boron nitrides with a specific three-dimensional porous fiber-like morphology and appropriate carbon doping have been developed and applied to the PDH-O 2 process, exhibiting outstanding performance during dehydrogenation stages. 148,149 This work provides a guide to structural design coupled with local atom regulation, achieving superior activity along with stability. Besides, other optional approaches such as co-feeding gas have also attracted intensive attention.…”

Unexpected Intrinsic Catalytic Function of Porous Boron Nitride Nanorods for Highly Efficient Peroxymonosulfate Activation in Water Treatment

“…The synthesis of porous BN was modified from the previous work, in which boric acid (H 3 BO 3 ) and melamine (C 3 N 6 H 6 ) were used as the starting materials. ,, Typically, 7.57 g (0.06 mol) of melamine and 7.42 g (0.12 mol) of boric acid were dispersed in 500 mL of DI water and heated to 85 °C to form a transparent solution. The clear solution was immediately chilled in an ice-water bath under sonication and transformed into a metastable hydrogel (Figure S1).…”