Selective transformation of renewable furfural catalyzed by diverse active species derived from 2D co-based metal-organic frameworks

- Two highly active catalytic species are generated from the 2D Co-based MOFs.
- The active species exhibit high activities for oxidative condensation of furfural.
- A 99% selectivity of 3-(furan-2-yl-)-2-methylacrylaldehyde has been obtained.
- The relationship between reaction activity and catalyst structure is discussed.
- No Co leaches and the observed catalysis (ACS-I and ACS-II) is truly heterogeneous in nature.

We report a facile method for gaining two different types of highly active species from the same 2D Co-based MOFs, which can effectively catalyze the selective transformation of biomass-derived furfural (FUR) in alcohols. Removal of the coordinated water molecules from the Co-based MOFs at 300 °C creates the open metal centers as catalytic active species (designated as ACS-I catalyst). Increasing the pyrolysis temperature to 700 °C, the derived multi-element carbon-matrix nanocomposite from the MOFs (designated as ACS-II catalyst) also shows highly catalytic performance. Both catalyst ACS-I and ACS-II exhibit high reactivity (84.9% conv.) and excellent selectivity (ca. 99.0%) in the oxidative condensation of FUR with n-propanol to produce 3-(furan-2-yl-)-2-methylacrylaldehyde (2) in the presence of molecular oxygen. The particular evidence for the role of metal Co centers in ACS-I and ACS-II is originated from the catalyst characterization and control experiments, in which Ni-I and Ni-II catalysts derived from isomorphrous 2D Ni-based MOFs show no catalytic activity on the transformation of FUR under the similar conditions.

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