Ce- and Y-Modified Double-Layered Hydroxides as Catalysts for Dry Reforming of Methane: On the Effect of Yttrium Promotion

Catalysts

Magnus Rønning¹  Monika Motak²  Teresa Grzybek²  Patrick Da Costa³  Katarzyna Świrk³  Patricia Beaunier⁴ 

[1] Department of Chemical Engineering, Norwegian University of Science and Technology, Sem Sælandsvei 4, N-7491 Trondheim, Norway;Faculty of Energy and Fuels, AGH University of Science and Technology, Adama Mickiewicza Avenue 30, 30-059 Cracow, Poland;Institut Jean Le Rond d’Alembert, Sorbonne Université, CNRS 7190, 2 Place de la Gare de Ceinture, F-78210 Saint-Cyr-l’École, France;Laboratoire Réactivité de Surface, Sorbonne Université, CNRS 7197, 4 place Jussieu, F-75005 Paris, France;

关键词: dry methane reforming;    double-layered hydroxides;    cerium;    yttrium;   

DOI  :  10.3390/catal9010056

来源: DOAJ

【 摘 要 】

Ce- and Y-promoted double-layered hydroxides were synthesized and tested in dry reforming of methane (CH4/CO2 = 1/1). The characterization of the catalysts was performed using X-ray fluorescence (XRF), X-ray diffraction (XRD), N2 sorption, temperature-programmed reduction in H2 (TPR-H2), temperature-programmed desorption of CO2 (TPD-CO2), H2 chemisorption, thermogravimetric analysis coupled by mass spectrometry (TGA/MS), Raman, and high-resolution transmission electron microscopy (HRTEM). The promotion with cerium influences textural properties, improves the Ni dispersion, decreases the number of total basic sites, and increases the reduction temperature of nickel species. After promotion with yttrium, the increase in basicity is not directly correlated with the increasing Y loading on the contrary of Ni dispersion. Dry reforming of methane (DRM) was performed as a function of temperature and in isothermal conditions at 700 °C for 5 h. For catalytic tests, a slight increase of the activity is observed for both Y and Ce doped catalysts. This improvement can of course be explained by Ni dispersion, which was found higher for both Y and Ce promoted catalysts. During DRM, the H2/CO ratio was found below unity, which can be explained by side reactions occurrence. These side reactions are linked with the increase of CO2 conversion and led to carbon deposition. By HRTEM, only multi-walled and helical-shaped carbon nanotubes were identified on Y and Ce promoted catalysts. Finally, from Raman spectroscopy, it was found that on Y and Ce promoted catalysts, the formed C is less graphitic as compared to only Ce-based catalyst.

【 授权许可】

Unknown