Amine-functionalized RUB-15 supported Pd and Zr nanoparticles: An efficient catalyst for hydrogen production from formic acid

This research focused on the production of hydrogen (H₂) from formic acid (FA) using palladium nanoparticles, promoted by zirconium, on amine-functionalized RUB-15. The 2%Pd-0.2%ZrO₂/RUB-15-NH₂ catalyst was produced through a hydrothermal technique and its physicochemical properties were characterized using various analyses including XRD, FTIR, BET, FE-SEM, TEM, EDS-dot mapping, CO₂-TPD, and TGA. These nanoparticles were successfully created with a small size of 3.75 nm and appropriate dispersions. Zirconium oxide (ZrO₂) induced significant electronic effects between Pd and RUB-15-NH₂ and strong interaction between Pd–ZrO₂ nanoparticles and RUB-15-NH₂. The dehydrogenation process with sodium formate (SF) additive was carried out at three different temperatures in a double-necked balloon under FA/SF = 1:1 condition. Overall, 2%Pd-0.2%ZrO₂/RUB-15-NH₂ exhibited satisfactory catalytic activity, 100% H₂ selectivity, no detectable CO production, and good reusability for H₂ production from FA. When SF was added to an FA aqueous solution for dehydrogenation, the total turnover frequency (TOF_total) and the initial TOF (TOF_initial) could reach 99.54 mol_CO2+H2 mol_pd⁻¹ h⁻¹ and 140 mol_CO2+H2 mol_pd⁻¹ h⁻¹ at 333 K, respectively. The stability test was measured in three cycles and showed great resistancy and activity during 140 min. The kinetic study was discussed and the first-order equation had a suitable result. Generally, the system's selectivity, high activity, stability, and simplicity in producing H₂/CO₂ gas without CO production from FA were the key features of this catalyst.