Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Article Citation - WoS: 12Citation - Scopus: 12Supercritical Fluid Reactive Deposition: a Process Intensification Technique for Synthesis of Nanostructured Materials(Elsevier, 2022) Yousefzadeh, Hamed; Akgün, Işık Sena; Barım, Şansım Bengisu; Sarı, Tarık Bercan; Eriş, Gamze; Uzunlar, Erdal; Bozbağ, Selmi Erim; Erkey, CanSupercritical fluid reactive deposition (SFRD) is a promising process intensification technique for synthesis of a wide variety of nanostructured materials. The enhanced mass transfer characteristics of supercritical fluids (SCFs) coupled with high solubilities of reducing gases in SCFs provide many advantages related to equipment size and time minimization over conventional techniques. Among SCFs, the emphasis has been placed on supercritical CO2 (scCO2) which is non-toxic, cheap and leaves no residue on the treated medium. Moreover, in SFRD, multiple processes such as dissolution, adsorption, reaction, and purification are combined in a single piece of equipment which is an excellent example of process integration for process intensification. In this review, the fundamental thermodynamic and kinetic aspects of the technology are described in detail. The studies in the literature on synthesis of a wide variety of nanostructured materials including supported nanoparticles, films, and ion-exchanged zeolites by SFRD are reviewed and summarized. The applications of these materials as catalysts and sensors are described. The review hopes to lead to further studies on further development of this technology for a wide variety of applications.Article Citation - WoS: 21Citation - Scopus: 21A Promising Catalyst for the Dehydrogenation of Perhydro-Dibenzyltoluene: Pt/Al2 O3 Prepared by Supercritical Co2 Deposition(MDPI, 2022) Modisha, Phillimon; Garidzirai, Rudaviro; Güneş, Hande; Bozbağ, Selmi Erim; Rommel, Sarshad; Uzunlar, Erdal; Aindow, Mark; Erkey, Can; Bessarabov, DmitriPt/Al2 O3 catalysts prepared via supercritical deposition (SCD), with supercritical CO2, wet impregnation (WI) methods and a selected benchmark catalyst, were evaluated for the dehydrogenation of perhydro-dibenzyltoluene (H18-DBT) at 300◦ C in a batch reactor. After ten dehydrogenation runs, the average performance of the catalyst prepared using SCD was the highest compared to the benchmark and WI-prepared catalysts. The pre-treatment of the catalysts with the product (dibenzyltoluene) indicated that the deactivation observed is mainly due to the adsorbed H0-DBT blocking the active sites for the reactant (H18-DBT). Furthermore, the SCD method afforded a catalyst with a higher dispersion of smaller sized Pt particles, thus improving catalytic performance towards the dehydrogenation of H18-DBT. The particle diameters of the SCD-and WI-prepared catalysts varied in the ranges of 0.6–2.2 nm and 0.8–3.4 nm and had average particle sizes of 1.1 nm and 1.7 nm, respectively. Energy dispersive X-ray spectroscopy analysis of the catalysts after ten dehydrogenation runs revealed the presence of carbon. In this study, improved catalyst performance led to the production of more liquid-based by-products and carbon material compared to catalysts with low catalytic performance.
