Researcher:
Çağlayan, Hatice Pelin

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Master Student

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Hatice Pelin

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Çağlayan

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Çağlayan, Hatice Pelin

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2022 - 20233

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Researcher Of Publications: search.filters.isAuthorOfPublication.633d0be8-2b18-41ab-a2e5-c6f38c5891d8

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    PublicationMetadata only
    Transformation of reduced graphene aerogel-supported atomically dispersed iridium into stable clusters approximated as Ir-6 during ethylene hydrogenation catalysis
    (Elsevier, 2022) Zhao, Yuxin; Hoffman, Adam S.; Gates, Bruce C.; Bare, Simon R.; Department of Chemistry; Department of Chemical and Biological Engineering; N/A; N/A; N/A; Ünal, Uğur; Uzun, Alper; Öztulum, Samira Fatma Kurtoğlu; Yalçın, Kaan; Çağlayan, Hatice Pelin; Faculty Member; Faculty Member; PhD Student; Master Student; Master Student; Department of Chemistry; Department of Chemical and Biological Engineering;  Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); College of Sciences; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; 42079; 59917; 384798; N/A; N/A
    Transformation of atomically dispersed reduced graphene aerogel (rGA)-supported complexes, Ir-I(C2H4)(2)(+), with an iridium loading of 9.9 wt%, to form low-nuclearity clusters was investigated during ethylene hydrogenation catalysis. Continuous-scan X-ray absorption spectra demonstrate the formation of clusters well approximated as Ir-4 during reaction at 100 degrees C in flowing equimolar ethylene and H-2. The Ir-4 clusters transformed into clusters well approximated as Ir 6 when the feed molar ratio was switched to H-2: C2H4 = 2 and remained stable in pure H-2 at 100 degrees C. Catalyst performance data show that hydrogenation activity increased with metal nuclearity in the order of atomically dispersed iridium/rGA << Ir-4/rGA < Ir-6/ rGA. Continuous scan X-ray absorption data, complemented with aberration-corrected scanning transmission electron microscopy images, demonstrate that the supported clusters approximated as Ir-6 are stable even in H-2 at atmospheric pressure and 100 degrees C. These supported iridium clusters are among the ones having the highest metal loadings reported for a supported metal cluster catalyst.
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    Effect of surface characteristics of graphene aerogels and hydrophilicity of ionic liquids on the CO2/CH4 separation performance of ionic liquid/reduced graphene aerogel composites
    (American Chemical Society (ACS), 2023) N/A; Department of Chemistry; Department of Chemical and Biological Engineering; Department of Chemical and Biological Engineering; Çağlayan, Hatice Pelin; Ünal, Uğur; Keskin, Seda; Uzun, Alper; Master Student; Faculty Member; Faculty Member; Faculty Member; Department of Chemistry; Department of Chemical and Biological Engineering; Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; College of Sciences; College of Engineering; College of Engineering; N/A; 42079; 40548; 59917
    Two ionic liquids (ILs) having the same cation with different anions offering opposite hydrophilic/hydrophobic characters, 1-n-butyl-1-methylpyrrolidinium dicyanamide ([BMPyr][DCA]) and 1-n-butyl-1-methylpyrrolidinium hexafluorophosphate ([BMPyr][PF6]), were impregnated onto two different reduced graphene aerogels (rGAs) prepared by the thermal treatment of GAs at 300 and 500 degrees C to investigate the consequences of the changes in the hydrophilic character of ILs and the reduction temperature of the GAs on the corresponding gas sorption and separation performance of the IL/rGAs. The structural analyses of nanoporous rGAs and IL/rGAs pointed to a change in the quantity of oxygenated functional groups upon thermal treatment and a change in the direct interactions between IL molecules and the host rGA surface upon IL deposition. Single-component CO2 and CH4 sorption measurements were performed for each rGA and IL/rGA composite, and both ideal and mixture CO2/CH4 selectivities were calculated. The samples prepared by reducing the GA at 300 and 500 degrees C yielded ideal CO2/ CH4 selectivities of 3.6 and 18 at 1 mbar and 25 degrees C, respectively. Among IL/rGA composites, the one prepared at 300 degrees C displayed a remarkable CO2/CH4 separation performance when combined with the hydrophobic [BMPyr][PF6], offering an ideal selectivity of 450.9 at 1 mbar and 25 degrees C, whereas the composite prepared with rGA500 yielded a substantially high CO2/CH4 selectivity of 173.5 after the incorporation of the hydrophilic [BMPyr][DCA] at 1 mbar and 25 degrees C. The ideal CO2/CH4 selectivities of [BMPyr][PF6]/ rGA300 and [BMPyr][DCA]/rGA500 surpassed most of the previously reported selectivities of carbon-based materials in the literature. These results demonstrate the broad potential of IL/rGAs in sorption-based gas separations owing to the highly tunable nature of both the structure of IL and the surface characteristics of rGA.
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    PublicationOpen Access
    Composites of porous materials with ionic liquids: synthesis, characterization, applications, and beyond
    (Elsevier, 2022) Department of Chemical and Biological Engineering; Durak, Özce; Zeeshan, Muhammad; Habib, Nitasha; Gülbalkan, Hasan Can; Alsuhile, Ala Abdulalem Abdo Moqbel; Çağlayan, Hatice Pelin; Öztulum, Samira Fatma Kurtoğlu; Zhao, Yuxin; Haşlak, Zeynep Pınar; Uzun, Alper; Keskin, Seda; PhD Student; PhD Student; Faculty Member; Department of Chemical and Biological Engineering; Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); College of Engineering; Graduate School of Sciences and Engineering; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; 59917; 40548
    Modification of the physicochemical properties of porous materials by using ionic liquids (ILs) has been widely studied for various applications. The combined advantages of ILs and porous materials provide great potential in gas adsorption and separation, catalysis, liquid-phase adsorption and separation, and ionic conductivity owing to the superior performances of the hybrid composites. In this review, we aimed to provide a perspective on the evolution of IL/porous material composites as a research field by discussing several different types of porous materials, including metal organic frameworks (MOFs), covalent organic frameworks (COFs), zeolites, and carbonaceous-materials. The main challenges and opportunities in synthesis methods, characterization techniques, applications, and future opportunities of IL/porous materials are discussed in detail to create a road map for the area. Future advances of the field addressed in this review will provide in-depth insights into the design and development of these novel hybrid materials and their replacement with conventional materials.