Methanation of CO2 over Ruthenium Supported on Alkali-Modified Silicalite-1 Catalysts

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 17; p. 6376
• Main Authors: Zieliński, Michał, Janiszewska, Ewa, Drewniak, Adrianna, Pietrowski, Mariusz
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 31-08-2023; MDPI
• Subjects: Alternative energy sources; Carbon dioxide; Chlorine; CO2 methanation; Energy industry; Fossil fuels; Hydrogenation; Microscopy; modified silicalite-1; Potassium; Renewable resources; ruthenium catalyst; Spectrum analysis; surface basicity; Temperature
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28176376

This study focuses on the catalytic properties of ruthenium catalysts supported on modified silicalite-1 (with an MFI structure). By post-synthesis modification of silicalite-1 with solutions of alkali metal compound, a novel and cost-effective method was discovered to create basic centers on the surface of silicalite-1 supports. The modification not only affected the basicity of the supports but also their porosity. The influence of the type of alkali solution (KOH or NaOH) and its concentration (0.1 M or 1.0 M) on both the basicity and porosity was investigated. The modified silicalite-1 materials were employed as supports for ruthenium catalysts (1 wt.% Ru) and evaluated for their CO2 methanation activity. The results were compared with the hydrogenation performance of ruthenium catalysts supported on unmodified silicalite-1. Characterization of the supports and catalysts was conducted using techniques such as BET, XRD, FT-IR, ICP-OES, TPR-H2, H2 chemisorption, TPD-CO2, SEM, and TEM. Remarkably, the catalytic activity of ruthenium supported on silicalite-1 treated with 1.0 M NaOH (exhibiting selectivity toward methane above 90% in a reaction temperature range of 250–450 °C) outperformed both unmodified and KOH-modified silicalite-1 supported Ru catalysts.