Mustafa Kømurcu

• Brogaard, Rasmus Yding; Kømurcu, Mustafa; Dyballa, Michael Martin; Botan, Alexandru; Van Speybroeck, Veronique; Olsbye, Unni & De Wispelaere, Kristof (2019). Ethene Dimerization on Zeolite-Hosted Ni Ions: Reversible Mobilization of the Active Site. ACS Catalysis.  ISSN 2155-5435.  9(6), s 5645- 5650 . doi: 10.1021/acscatal.9b00721
• Henry, Reynald; Kømurcu, Mustafa; Ganjkhanlou, Yadolah; Brogaard, Rasmus Yding; Li, Lu; Jens, Klaus-Joachim; Berlier, Gloria & Olsbye, Unni (2017). Ethene oligomerization on nickel microporous and mesoporous-supported catalysts: Investigation of the active sites. Catalysis Today.  ISSN 0920-5861.  299(Jan), s 154- 163 . doi: 10.1016/j.cattod.2017.04.029 Vis sammendrag

  Nickel-containing mesoporous (using Al2O3 or SiO2-Al2O3 support) and microporous (using nano- or micro-crystalline Beta zeolite support) catalysts were prepared by ion exchange and characterized by XRD, SEM, N2-adsorption, MP-AES and FTIR. The samples were subjected to testing as ethene oligomerization catalysts at T = 120 °C, Ptotal = 29 bar, Pethene = 11.6–25.1 bar. All catalysts were active for ethene oligomerization, and linear butenes were the main gaseous products. However, catalyst deactivation due to retained long-chain alkenes was observed. Ethene partial pressure variation experiments showed that the reaction order in ethene for butene formation was 1.5–1.7 for the mesoporous, and 2.0 for the microporous catalysts. Contact time variation experiments carried out with the microporous catalysts at Pethene = 18 bar showed that product selectivity was independent of ethene conversion, and suggested that 1-butene and 2-butenes are primary products. This result is consistent with the Cossee-Arlman mechanism. The nature of the active sites was investigated with FTIR spectroscopy with CO as probe molecule. The results point to Ni2+-counterions as the preeminent active sites, while we suggest that Ni-sites grafted on silanol groups and NiO particles are spectators.

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• Kømurcu, Mustafa & Olsbye, Unni (2018). Ethene oligomerization over Ni-containing beta zeolite.
• Kømurcu, Mustafa; Olsbye, Unni & Reynald, Henry (2016). Ethene oligomerization on nickel containing beta zeolite catalyst. Vis sammendrag

  This thesis is part of a project aimed at developing new catalysts for the ethene oligomerization reaction. Ni/Beta zeolite was selected as model material, based on the combined advantage of the metal function and the shape-selective support material. The thesis was aimed to focus on catalytic kinetic studies, as a means of elucidating mechanistic information about the reaction and of developing innovative oligomerization catalysts. Ni-containing beta zeolite was prepared both by nickel impregnation and ion exchange and characterized by: XRD, MP-AES, N2-physisorption and SEM. It was found that bulk NiO clusters were formed with nickel impregnation. The catalytic studies were performed on nickel ion exchanged samples that showed far less bulk NiO clusters. Based on previous work on this reaction in the group and literature survey, it was found that a high ethene partial pressure is necessary for significant ethene conversion over zeolite-based catalysts. For this purpose the construction of a test-rig that can operate under high pressure was started at the same time as this work began. During the construction of the rig, several obstacles were encountered and a lot of effort was made to prepare the high pressure test-rig for catalytic testing. Prior to the results reported in this thesis, a handful of experiments were reproduced from literature in order to verify the viability of the reactor for this kind of experiments. Catalytic studies revealed that nickel is essential for ethene oligomerization under mild reaction conditions; one order of magnitude higher conversion was obtained with nickel containing Beta zeolite compared to the proton form. Deactivation of the catalysts was observed with time on stream and it was found to be due to aliphatic hydrocarbons produced during the reaction. Nanocrystalline Ni-Beta showed no deactivation with time on stream which is suggested to be due to shorter diffusion path for the heavy products formed during the reaction. A series of catalytic tests revealed that the reaction mechanism is independent of P(ethene) between 11.6 – 25.1 bar and a second order reaction rate for linear butene formation was found. The Cossee-Arlman mechanism is suggested to be the most likely reaction mechanism, without definitely excluding metallacycle mechanism.

• Brogaard, Rasmus Yding; Kømurcu, Mustafa; Ganjkhanlou, Yadolah; Henry, Reynald Philippe; Berlier, Gloria; Bleken, Bjørn Tore Lønstad; Groppo, Elena; Bordiga, Silvia & Olsbye, Unni (2015). Ethene Oligomerization in Ni-zeolites: Investigating the Reaction Mechanism..

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