Plasma-assisted Ru/Zr-MOF catalyst for hydrogenation of CO₂ to methane

Abstract

As an important type of metal-organic framework (MOF), Zr-MOF shows excellent CO 2 adsorption performance. In this work, a Zr-MOF was synthesized by a solvothermal method and adopted to support Ru through simple incipient-wetness impregnation. Then the Ru/Zr-MOF was applied for CO 2 hydrogenation = ( )with the assistance of dielectric barrier discharge (DBD) plasma. The hydrogenation of CO 2 results showed that methane was produced selectively under the synergistic effect between plasma and the Ru/Zr-MOF catalyst, and the selectivity and yield of methane reached 94.6% and 39.1%, respectively. The XRD and SEM analyses indicate that the basic crystalline phase structure and morphology of the Zr-MOF and Ru/Zr-MOF remained the same after DBD plasma treatment, suggesting that the catalysts are stable in plasma. The guest molecules in the pores of the Zr-MOF are removed and the Ru 3+ ions are reduced to metallic Ru 0 in the reduction atmosphere according to the BET and XPS results, which are responsible for the high performance of plasma with the Ru/Zr-MOF catalyst. In situ optical emission spectra of pure plasma, plasma with Zr-MOF, and plasma with Ru/Zr-MOF were measured, and the active species of C, H and CH for CO 2 hydrogenation were detected. The plasma-assisted Ru/Zr-MOF exhibited high catalytic activity and stability in CO 2 hydrogenation to methane, and it has great guiding significance for CO 2 hydrogenation by using plasma and MOF materials.

A Facile Method for Preparing UiO-66 Encapsulated Ru Catalyst and its Application in Plasma-Assisted CO2 Methanation

“…The activity of Ru@UiO-66 and UiO-66 for plasma-assisted catalytic CO 2 methanation were tested, as illustrated in Figure 9. For comparison, the activity data of Ru/UiO-66 (UiO-66 supported Ru prepared by incipient wetness impregnation method) taken from a previous work [38] was also illustrated in Figure 9. The loading amount of Ru in Ru@UiO-66 and Ru/UiO-66 are close, and the reaction was performed under the same experimental parameters.…”

“…The strategy for preparing UiO-66 and Ru@UiO-66 is depicted in Figure 1. UiO-66 was prepared by a solvent thermal method previously reported in [38]. In brief, 1.165 g of ZrCl 4 and 0.831 g of BDC were dissolved in 30 mL DMF, and then 0.8 mL of concentrated HCl (37%) was added.…”

“…Dielectric barrier discharge (DBD) plasma-assisted CO 2 conversion over UiO-66, Ru@UiO-66, and Ru/UiO-66, Reproduced from [38], Copyright Hefei Institutes of Physical Science, Chinese Academy of Sciences and IOP Publishing, 2019.…”

Dielectric Barrier Discharge Plasma-Assisted Catalytic CO2 Hydrogenation: Synergy of Catalyst and Plasma

“…As another representative noble metal, Ru has been proven active for CO 2 hydrogenation in previous studies with HCOO-as the intermediate [56]. Interestingly, Ru 3+ could be in-situ reduced to Ru metallic phase, which exhibited a highly selective methanation via CO 2 hydrogenation [57]. The combination of DBD plasma and Ru enabled the successive deoxygenation of CO 2 and further conversion to CH 4 [37].…”

“…Owing to the outstanding adsorption capability of CO 2 , Zr-MOF exhibits great potential in CO 2 hydrogenation [57]. Moreover, the high surface area and abundant surface hydroxyl groups benefit the dispersion of active metals [106][107][108].…”