Construction of frustrated Lewis pairs on carbon nitride nanosheets for catalytic hydrogenation of acetylene

• Published in: Physical chemistry chemical physics : PCCP 2021-11, Vol.23 (42), p.24349-24356
• Main Authors: Wan, Qiang, Li, Juan, Jiang, Rong, Lin, Sen
• Format: Article
• Language: English
• Subjects: Acetylene; Carbon; Carbon nitride; Catalysts; Density functional theory; Electron transfer; Electronic structure; Hydrogenation; Nanosheets; Noble metals; Structural analysis
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d1cp03592d

Here, we studied Al or B atom-doped carbon nitride (g-C 3 N 4 and C 2 N) as catalysts for H 2 activation and acetylene hydrogenation using density functional theory calculations. The Al or B could be assembled with the surface N atoms of carbon nitride to form diverse frustrated Lewis pairs (FLPs). The results show that Al-N FLPs had lower barriers of H 2 activation in comparison with B-N FLPs. The heterolytic H 2 dissociation catalyzed by Al-N FLPs led to the formation of Al-H and N-H species. The Al-H species were highly active in the first hydrogenation of acetylene to C 2 H 3 *, yielding a mild barrier, while in the second hydrogenation step, the reaction between C 2 H 3 and the H of N-H species caused a relatively high barrier. Electronic structure analysis demonstrated the electron transfer in the heterolytic H 2 cleavage and explained the activity differences in various FLPs. The results suggest that Al with the surface N of carbon nitride can act as an FLP to catalyze the H 2 activation and acetylene hydrogenation, thus providing a new strategy for the future development of noble metal-free hydrogenation catalysts. Al-N frustrated Lewis pairs on carbon nitride nanosheets for efficient hydrogenation of acetylene.