Journal
ACS CATALYSIS
Volume 9, Issue 4, Pages 3266-3277Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acscatal.8b05180
Keywords
cellulose nanocrystals; heterogeneous organocatalysis; aldol condensation; furfural; acid-base; cooperative catalysis; site pairing; optimization
Categories
Funding
- Renewable Bioproducts Institute at the Georgia Institute of Technology through a Paper Science and Engineering Fellowship
Ask authors/readers for more resources
Cellulose nanocrystals (CNCs) are demonstrated as effective, ordered supports for cooperative acid-base heterogeneous organocatalysis, offering an alternative to typical silica supports. CNC catalyst surface chemistry is optimized through quantitative control of the loadings of carboxylic acids, primary amines, and sulfate half-esters, as characterized by elemental analysis, conductometric titration, and FT-IR spectroscopy. Catalysts are evaluated in the liquid phase aldol condensation of 4-nitrobenzaldehyde or furfural with acetone. Carboxylic are effective cooperative acid partners in CNC organocatalysts, and site-specific activity is strongly correlated with the COOH:NH2 ratio. Partial sulfate half-ester removal, high acid/base ratios, and use of unprotected diamines in the catalyst synthesis lead to optimized CNC catalyst function (site-time yield = 1.0 x 10(-4) s(-1)). High selectivities to dehydrated aldol products (>80%) are achieved due to the acid content of the CNC catalysts. CNC catalysts outperform analogous SBA-15-supported aminosilica catalysts in regard to both activity and selectivity. Crystalline surface structures and ordered chemical functionalization in CNCs appear advantageous for precise design and control of bifunctional acid-base cooperative catalysts.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available