Researcher:
Akarçay, Özge

Profile Picture
ORCID

Job Title

PhD Student

First Name

Özge

Last Name

Akarçay

Name

Name Variants

Akarçay, Özge

Email Address

Birth Date

Filters

2018 - 20202

Advanced Search

Filter by

Settings

Researcher Of Publications: search.filters.isAuthorOfPublication.4a53bb2d-c8a7-4e21-8fdd-99cc523b58be

Search Results

Now showing 1 - 2 of 2
  • Placeholder
    PublicationMetadata only
    Isobutene oligomerization on MCM-41-supported tungstophosphoric acid
    (Elsevier Science Bv, 2018) Çelebi, Serdar; N/A; N/A; N/A; Department of Chemical and Biological Engineering; Kocaman, Elif; Akarçay, Özge; Bağlar, Nur; Uzun, Alper; Master Student; 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); Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; N/A; 59917
    Oligomerization offers a broad potential for converting light olefins into liquid fuels. Here, tungstophosphoric acid, TPA, was impregnated on a mesoporous silica support, MCM-41, at varying loadings from 1 to 90 wt%. The IR and XRD results indicated the presence of interactions between the WA clusters and MCM-41, especially at loadings below 50 wt%. These interactions led to variations in acid site density and their corresponding strength as evidenced by the results of temperature programmed desorption of ammonia measurements. Consequences of these changes were investigated on isobutene oligomerization. Results obtained at 393 K and 15 bar indicated that the TPA/MCM-41 catalysts provide more than 75 wt% isobutene conversions at a weight hourly space velocity (WHSV) of 46 h(-1). Results further showed that the catalysts were more selective towards distillate range products especially at very low TPA loadings. The relative selectivity of trimers over dimers in the oligomerization product pool was approximately four at a TPA loading of 1 wt% and it decreased to 1.5 with increasing TPA loading. Ruling out the presence of any strong correlations between acid strength and catalytic performance, the data presented a strong dependence of the product selectivity on the availability and vicinity of the acid sites.
  • Placeholder
    PublicationMetadata only
    Ammonia decomposition on a highly-dispersed carbon-embedded iron catalyst derived from Fe-BTC: stable and high performance at relatively low temperatures
    (Elsevier, 2020) N/A; N/A; Department of Chemical and Biological Engineering; Akarçay, Özge; Öztulum, Samira Fatma Kurtoğlu; Uzun, Alper; PhD Student; PhD Student; Faculty Member; Department of Chemical and Biological Engineering; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 384798; 59917
    Fe-BTC (iron 1,3,5-benzenetricarboxylic acid), a commercially available metal organic framework (MOF), was used as a sacrificial template to produce a series of carbon-embedded Fe catalysts upon its pyrolysis at different temperatures. The catalyst prepared by pyrolyzing Fe-BTC at 400 degrees C under flowing N-2 provided a high graphitic degree on the carbon support hosting highly dispersed Fe species at a Fe loading of 34 wt%. Performance measurements on ammonia decomposition to produce COx-free hydrogen showed that this catalyst provided an ammonia conversion of 73.8% at a space velocity of 6000 cm(3) NH3 h(-1) g(cat)(-1) and at 500 degrees C for at least 120 h. This stable performance, exceeding that of some of the best non-noble metal catalysts, was associated with the presence of highly-dispersed Fe species at a significantly high Fe loading, embedded in a carbonaceous shell. The presence of the carbonaceous shell not only protected the active species against sintering, but also made them electron rich owing to its high level of graphitization.