Enhancement of solid base activity for porous boron nitride catalysts by controlling active structure using post treatment

[Display omitted] •Porous boron nitride solid base catalysts were synthesized by a pyrolysis method.•A post-treatment rather than the synthesis conditions greatly affected the activity.•11B MAS NMR spectroscopy showed that BOx species were removed by the washing process.•The post-treated BN was show...

Full description

Saved in:
Bibliographic Details
Published in:Applied catalysis. A, General General, 2020-11, Vol.608, p.117843, Article 117843
Main Authors: Takagaki, Atsushi, Nakamura, Shohei, Watanabe, Motonori, Kim, Yoonyoung, Song, Jun Tae, Jimura, Keiko, Yamada, Kanta, Yoshida, Masaaki, Hayashi, Shigenobu, Ishihara, Tatsumi
Format: Article
Language:English
Subjects:
11B MAS NMR
Active control
Ammonia
B K-edge XAFS
Boron
Boron nitride
Boron oxides
Catalysts
Fine structure
Flow velocity
Fourier transforms
Nitroaldol reaction
NMR spectroscopy
Pyrolysis
Solid base catalyst
Spectrum analysis
Synthesis
Washing
X ray absorption
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •Porous boron nitride solid base catalysts were synthesized by a pyrolysis method.•A post-treatment rather than the synthesis conditions greatly affected the activity.•11B MAS NMR spectroscopy showed that BOx species were removed by the washing process.•The post-treated BN was shown to contain moderately strong basic sites. Porous boron nitride (BN) was synthesized using a pyrolysis method in conjunction with varying NH3 flow rates, followed by washing as a post-treatment. The performance of this material as a solid base catalyst was assessed. It was found that the post-treatment rather than the synthesis conditions significantly improved the activity of the BN during the nitroaldol reaction. The BN catalyst obtained after washing gave a ten times higher product yield. Both an increase in the surface areas of the material and the emergence of micropores after washing were observed. 11B solid-state nuclear magnetic resonance spectroscopy demonstrated that boron oxide species were present in the BN after synthesis but were removed by the washing process. B K-edge X-ray absorption fine structure analyses indicated the formation of oxygen-substituted trigonal boron sites on the BN surface. Fourier transform infrared spectroscopy showed that amino groups on the samples functioned as moderately strong basic sites.
ISSN:0926-860X
1873-3875
DOI:10.1016/j.apcata.2020.117843