Post-Synthesis Modification of Zirconium(IV)-BTC Based MOF with Palladium Nanoparticles as Catalyst in the Hydrogenation Reaction of Citronellal

Witri Wahyu Lestari, Disa Ayudia, Riandy Putra, Fauzan Ibnu Prihadiyono, Maulidan Firdaus, Venansia Avelia Rosari, Ubed SF Arrozi, Grandprix TM Kadja, Yudha P. Budiman
https://doi.org/10.1007/s10904-023-02909-0

Abstract

The objective of this research is to investigate the effect of palladium insertion into zirconium(IV)-based Metal-Organic Frameworks (MOFs) containing a benzene 1,3,5-benzenetricarboxylate organic linker [Pd/Zr₆O₄(OH)₄(O₂C₂H₃)₆(BTC)₂] or (Pd/Zr-BTC) on its structure and its ability to catalyze the hydrogenation process of citronellal. Zr-BTC was synthesized by a modulated-solvothermal method at 135 °C. Post-synthesis modification with Pd nanoparticle was conducted using the wet impregnation method with a concentration of 2.5% (w/w). Powder XRD analysis showed that the presence of Pd was identified by a new peak at 2θ = 40.0° and the decrease of Zr-BTC crystallinity. The presence of Pd also increases the irregularity of Zr-BTC morphology and contains an average particle size up to 16.58 ± 6.4 nm according to SEM and TEM analysis. Modification with Pd lead to a decrease in surface area, pore volume, and diameter of Zr-BTC up to 1095 m²/g, 0.15 cc/g, and 18.6 Å, respectively. Moreover, the addition of Pd does not affect the thermal stability of Zr-BTC. An examination of the hydrogenation of citronellal was carried out using two distinct setups. The first involved conducting reactions in a batch reactor system at a temperature of 80 °C and under a hydrogen pressure of 10 bar for a duration of 6 h. The second approach entailed performing reactions in a hydrogen-filled balloon under atmospheric pressure (1 atm) at 80 °C for a period of 6 h. The addition of Pd into Zr-BTC increases its activity up to 83.2%, and selectivity (up to 53.7%) in citronellal hydrogenation for both batch and balloon systems. Interestingly, the employment of batch reactors is found to be more effective.

Keywords:

Zr-BTC; Solvothermal; Palladium; Hydrogenation; Citronellal