Campus Units

Chemical and Biological Engineering, NSF Engineering Research Center for Biorenewable Chemicals

Document Type

Article

Research Focus Area

Advanced and Nanostructured Materials, Biorenewables, Catalysis and Reaction Engineering

Publication Version

Submitted Manuscript

Publication Date

4-2-2020

Journal or Book Title

ACS Sustainable Chemistry & Engineering

DOI

10.1021/acssuschemeng.0c00278

Abstract

Glucose isomerization to fructose is one of the most important reactions in the field of biomass valorization. We demonstrate wood waste valorization with MgCl2 salt to synthesize an environment-friendly catalyst (i.e., MgO-biochar), which exhibits effective glucose-to-fructose isomerization with over 30% fructose yield and 80% selectivity at only 100 °C for 30 min in water as a green medium. This study highlights that one-step synthesis can effectively disperse and tether MgO nanostructures to the biochar matrix, which displays a significant reduction of Mg leaching compared to MgO-biochars produced by two-step synthesis and pure MgO. The MgCl2 acts as a porogen that facilitates the formation of a porous biochar structure and dispersion of nanostructured MgO. We identify key parameters of impregnation media (ethylene glycol, ethanol, and water) and pyrolysis conditions (600/750 °C in N2/CO2 atmosphere) that are responsible for adjusting the reactivity and stability of MgO, which enable the design of more effective and recyclable biochar catalysts. Weak interactions between MgCl2 and biomass in the presence of aqueous miscible organic solvents as shape-directing agents are accountable for fast leaching of Mg from the MgO-biochar surface. The FTIR spectra confirm the existence of various coordinations on the hydroxylated surfaces of MgO-biochar surfaces. The mesoporous structures of the biochar support enhance the stability of MgO moieties as revealed by BET, XRD, and Raman analyses. Given the benefits of effective MgO dispersion on the biochar support, we can reduce the amount of MgO active species involved in each reaction run, which mitigates over-reaction compared to pure MgO catalysts and achieves high fructose yield and selectivity for three consecutive cycles.

Comments

This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in ACS Sustainable Chemistry & Engineering, copyright © American Chemical Society after peer review. To access the final edited and published work see DOI: 10.1021/acssuschemeng.0c00278. Posted with permission.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Published Version

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