Issue 9, 2016

Synergetic catalysis of palladium nanoparticles encaged within amine-functionalized UiO-66 in the hydrodeoxygenation of vanillin in water

Abstract

Ultrasmall palladium nanoparticles (1.5–2.5 nm) encapsulated in metal–organic frameworks (MOFs) have been prepared by introducing a palladium precursor into a highly porous and hydrothermally stable amine-functionalized UiO-66 (NH2-UiO-66) via a direct anionic exchange and subsequent H2 reduction. The prepared Pd@NH2-UiO-66 catalyst was then applied in the hydrodeoxygenation of vanillin (a typical model compound of lignin) at a low H2 pressure in aqueous media. Excellent catalytic results (100% conversion of vanillin with exclusive selectivity for 2-methoxy-4-methylphenol) could be achieved over the developed 2.0 wt% Pd@NH2-UiO-66 catalyst under mild conditions. Furthermore, the catalytic activity and selectivity were not affected after six reaction cycles indicating excellent stability and reproducibility of this catalyst system. It was found that the presence of free amine groups in the framework of NH2-UiO-66 plays a key role in the formation of uniform, well-dispersed and leaching resistant palladium nanoparticles within the MOF host. Moreover, the developed Pd@NH2-UiO-66 exhibits a novel synergetic catalysis in the hydrodeoxygenation due to the cooperation between the well-dispersed metallic Pd sites and the amine-functionalized MOF support, in which Pd offers hydrogenation activity and the MOF support facilitates hydrogenolysis of the intermediate vanillin alcohol to the 2-methoxy-4-methylphenol product.

Graphical abstract: Synergetic catalysis of palladium nanoparticles encaged within amine-functionalized UiO-66 in the hydrodeoxygenation of vanillin in water

Supplementary files

Article information

Article type
Paper
Submitted
30 Oct 2015
Accepted
26 Jan 2016
First published
27 Jan 2016

Green Chem., 2016,18, 2900-2908

Author version available

Synergetic catalysis of palladium nanoparticles encaged within amine-functionalized UiO-66 in the hydrodeoxygenation of vanillin in water

F. Zhang, S. Zheng, Q. Xiao, Y. Zhong, W. Zhu, A. Lin and M. Samy El-Shall, Green Chem., 2016, 18, 2900 DOI: 10.1039/C5GC02615F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements