%0 Journal Article %1 pappas2019cuexchanged %A Pappas, Dimitrios K. %A Borfecchia, Elisa %A Lomachenko, Kirill A. %A Lazzarini, Andrea %A Gutterød, Emil S. %A Dyballa, Michael %A Martini, Andrea %A Berlier, Gloria %A Bordiga, Silvia %A Lamberti, Carlo %A Arstad, Bjørnar %A Olsbye, Unni %A Beato, Pablo %A Svelle, Stian %D 2019 %J Topics in Catalysis %K %N 7 %P 712-723 %R 10.1007/s11244-019-01160-7 %T Cu-Exchanged Ferrierite Zeolite for the Direct CH4 to CH3OH Conversion : Insights on Cu Speciation from X-Ray Absorption Spectroscopy %V 62 %X The direct stepwise transformation of CH4 to CH3OH over Cu-exchanged zeolites has been an intensively researched reaction as it can provide a solution for the utilization of this abundant feedstock. Up to date a commercial process is far from realization, which is why an understanding of the Cu speciation in zeolites as a function of reaction conditions as well as the development of a mechanistic view of the reaction are necessary to further advance the field. Herein we study Cu-exchanged ferrierite zeolite for the direct CH4 to CH3OH conversion by utilizing X-ray absorption spectroscopy (XAS), in order to assess the local structure and electronic properties of Cu through the reaction. A Cu-FER sample with a Cu/Al = 0.20 and Si/Al = 11 was subjected to three reaction cycles yielding ultimately 96 mmol CH3OH / g zeolite. Normalized to the Cu loading, this accounts for 0.33 mol CH3OH / mol Cu, making the sample comparable to very active Cu-MOR materials reported in the literature. During O2 activation, a transient self-reduction regime of CuII to CuI ions was identified; eventually leading to mostly framework interacting CuII species. CH4 loading leads to a reduction of these CuII containing species; which are finally partially reoxidized during H2O-assisted CH3OH extraction. The speciation after CH4 activation as well as H2O-assisted CH3OH extraction was assessed via linear combination fitting analysis of the XAS data.

@article{pappas2019cuexchanged, abstract = {The direct stepwise transformation of CH4 to CH3OH over Cu-exchanged zeolites has been an intensively researched reaction as it can provide a solution for the utilization of this abundant feedstock. Up to date a commercial process is far from realization, which is why an understanding of the Cu speciation in zeolites as a function of reaction conditions as well as the development of a mechanistic view of the reaction are necessary to further advance the field. Herein we study Cu-exchanged ferrierite zeolite for the direct CH4 to CH3OH conversion by utilizing X-ray absorption spectroscopy (XAS), in order to assess the local structure and electronic properties of Cu through the reaction. A Cu-FER sample with a Cu/Al = 0.20 and Si/Al = 11 was subjected to three reaction cycles yielding ultimately 96 mmol CH3OH / g zeolite. Normalized to the Cu loading, this accounts for 0.33 mol CH3OH / mol Cu, making the sample comparable to very active Cu-MOR materials reported in the literature. During O2 activation, a transient self-reduction regime of CuII to CuI ions was identified; eventually leading to mostly framework interacting CuII species. CH4 loading leads to a reduction of these CuII containing species; which are finally partially reoxidized during H2O-assisted CH3OH extraction. The speciation after CH4 activation as well as H2O-assisted CH3OH extraction was assessed via linear combination fitting analysis of the XAS data.}, added-at = {2023-08-31T16:06:29.000+0200}, author = {Pappas, Dimitrios K. and Borfecchia, Elisa and Lomachenko, Kirill A. and Lazzarini, Andrea and Gutterød, Emil S. and Dyballa, Michael and Martini, Andrea and Berlier, Gloria and Bordiga, Silvia and Lamberti, Carlo and Arstad, Bjørnar and Olsbye, Unni and Beato, Pablo and Svelle, Stian}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2f00065a1a697d4a31cbe200093ec0eea/puma-wartung}, doi = {10.1007/s11244-019-01160-7}, interhash = {b13f9ffbaf3d4e11afef15359043bb56}, intrahash = {f00065a1a697d4a31cbe200093ec0eea}, issn = {1572-9028}, journal = {Topics in Catalysis}, keywords = {}, language = {eng}, number = 7, pages = {712-723}, timestamp = {2023-08-31T14:06:29.000+0200}, title = {Cu-Exchanged Ferrierite Zeolite for the Direct CH4 to CH3OH Conversion : Insights on Cu Speciation from X-Ray Absorption Spectroscopy}, volume = 62, year = 2019 }