Hydrogenative Ring-Rearrangement of Biobased FuranicAldehydes to Cyclopentanone Compounds over Pd/Pyrochlore by IntroducingOxygen Vacancies
2020
Upgrading
furanic aldehydes (such as furfural or 5-hydroxymethyl
furfural) to cyclopentanone compounds (such as cyclopentanone or 3-hydroxymethyl
cyclopentanone) is of great significance for the synthesis of high-value
chemicals and biomass utilization. Developing an efficient reduced
metal/acidic support with Lewis acidity is the key to facilitating
the carbonyl hydrogenation and hydrolysis steps in the hydrogenative
ring-rearrangement reaction. Herein, three pure Lewis acidic pyrochlore
supports of the form A2B2O7 (La2Sn2O7, Y2Sn2O7, and Y2(Sn0.7Ce0.3)2O7‑δ) with the same crystal structures
and different metals are synthesized. The Lewis acidity and the surface
properties of the pyrochlore can be tuned by inserting different kinds
of A and B site metals. After impregnation, Pd nanoparticles with
appropriate particle sizes are uniformly loaded on the surface of
pyrochlore. For the reaction of the furanic aldehydes, all of these
pyrochlore-based catalysts exhibit hydrogenation and hydrolysis rates
that are both faster than those of traditional support-based catalysts
due to the oxygen vacancy and pure Lewis acidity of the support. Among
these pyrochlore-based catalysts, Pd/Y2Sn2O7 exhibits activity and selectivity that are higher than those
of Pd/La2Sn2O7. Moreover, the Y2Sn2O7-based catalyst partially substituted
by Ce3+ ions at the B site is more efficient, with the
highest cyclopentanone yield and 3-hydroxymethyl cyclopentanone yield
of 95.0% and 92.5%, respectively. Furthermore, the catalyst can still
maintain an effective activity and stability after 4 runs. This study
not only presents an efficient biobased route for the production of
cyclopentanone compounds but also focuses on the acid catalytic performance
of pyrochlore based on its pure Lewis acidity.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
59
References
22
Citations
NaN
KQI