%0 Journal Article %1 Pappas2019 %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 %U https://doi.org/10.1007/s11244-019-01160-7 %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/Alþinspace=þinspace0.20 and Si/Alþinspace=þinspace11 was subjected to three reaction cycles yielding ultimately 96 µmol\$\$\_\\\\backslashtext\C\\\\\backslashtext\H\\\_3\\\backslashtextØH\\\\/\\\backslashtext\g\\\_\\\backslashtext\zeolite\\\\\$\$CH3OH/gzeolite. Normalized to the Cu loading, this accounts for 0.33 mol\$\$\_\\\\backslashtext\C\\\\\backslashtext\H\\\_3\\\backslashtextØH\\\\\$\$CH3OH/molCu, 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{Pappas2019, 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{\thinspace}={\thinspace}0.20 and Si/Al{\thinspace}={\thinspace}11 was subjected to three reaction cycles yielding ultimately 96 {\textmu}mol{\$}{\$}{\_}{\{}{\{}{\{}{\backslash}text{\{}C{\}}{\}}{\{}{\{}{\backslash}text{\{}H{\}}{\}}{\_}3{\}}{\{}{\backslash}text{\{}OH{\}}{\}}{\}}{\}}/{\{}{\{}{\backslash}text{\{}g{\}}{\}}{\_}{\{}{\{}{\backslash}text{\{}zeolite{\}}{\}}{\}}{\}}{\$}{\$}CH3OH/gzeolite. Normalized to the Cu loading, this accounts for 0.33 mol{\$}{\$}{\_}{\{}{\{}{\{}{\backslash}text{\{}C{\}}{\}}{\{}{\{}{\backslash}text{\{}H{\}}{\}}{\_}3{\}}{\{}{\backslash}text{\{}OH{\}}{\}}{\}}{\}}{\$}{\$}CH3OH/molCu, 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 = {2020-05-15T11:51:55.000+0200}, author = {Pappas, Dimitrios K. and Borfecchia, Elisa and Lomachenko, Kirill A. and Lazzarini, Andrea and Gutter{\o}d, Emil S. and Dyballa, Michael and Martini, Andrea and Berlier, Gloria and Bordiga, Silvia and Lamberti, Carlo and Arstad, Bj{\o}rnar and Olsbye, Unni and Beato, Pablo and Svelle, Stian}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/20983dc357a1fd9d93dc53f1969c4e354/ingo}, day = 01, doi = {10.1007/s11244-019-01160-7}, interhash = {cffde86f405f21b8ff5995d9d500be47}, intrahash = {0983dc357a1fd9d93dc53f1969c4e354}, issn = {1572-9028}, journal = {Topics in Catalysis}, keywords = {}, month = aug, number = 7, pages = {712--723}, timestamp = {2020-05-15T09:51:55.000+0200}, title = {Cu-Exchanged Ferrierite Zeolite for the Direct CH4 to CH3OH Conversion: Insights on Cu Speciation from X-Ray Absorption Spectroscopy}, url = {https://doi.org/10.1007/s11244-019-01160-7}, volume = 62, year = 2019 }