Ultrasound and Microwave-Assisted Synthesis of Hexagonally Ordered Ce-Promoted Mesoporous Silica as Ni Supports for Ethanol Steam Reforming
Jorge Tovar-Rodriguez,
Emiliano Fratini,
Piero Baglioni,
Carlo Ferrari,
José Antonio de los Reyes-Heredia,
Yonatan Ramírez-Hernández,
Ignacio René Galindo-Esquivel
Affiliations
Jorge Tovar-Rodriguez
Department of Chemistry “Ugo Schiff” and Center for Colloid and Surface Science (CSGI), University of Florence, Via della Lastruccia 3, 50019 Florence, Italy
Emiliano Fratini
Department of Chemistry “Ugo Schiff” and Center for Colloid and Surface Science (CSGI), University of Florence, Via della Lastruccia 3, 50019 Florence, Italy
Piero Baglioni
Department of Chemistry “Ugo Schiff” and Center for Colloid and Surface Science (CSGI), University of Florence, Via della Lastruccia 3, 50019 Florence, Italy
Carlo Ferrari
National Institute of Optics (INO–UOS Pisa), National Council of Research (CNR), Via Giuseppe Moruzzi 1, 56124 Pisa, Italy
José Antonio de los Reyes-Heredia
Process Engineering and Hydraulics Department, Metropolitan Autonomous University, UAM, Av. San Rafael Atlixco 186, Ciudad de México 09340, Mexico
Yonatan Ramírez-Hernández
Chemical Engineering Department, University of Guanajuato, Noria Alta S/N, Noria Alta, Guanajuato 36050, Mexico
Ignacio René Galindo-Esquivel
Chemical Engineering Department, University of Guanajuato, Noria Alta S/N, Noria Alta, Guanajuato 36050, Mexico
Solvothermal synthesis of mesoporous materials based on amphiphilic molecules as structure-directing agents can be enhanced using non-conventional technologies for stirring and thermal activation. Here, we disclose a green synthesis approach for the preparation of cerium-modified hexagonally ordered silica sieves. Ultrasound micromixing enabled us to obtain well-dispersed Ce in the self-assembled silica network and yielded ordered materials with high cerium content (Ce/Si molar ratio = 0.08). Microwave dielectric heating, applied by an innovative open-end coaxial antenna, was used to reduce the overall hydrothermal synthesis time and to improve the surface area and textural properties. These mesoporous materials were used as a Ni catalyst support (10 wt.% metal loading) for the ethanol steam reforming reaction. The new catalysts featured complete ethanol conversion, high H2 selectivity (65%) and better stability, compared to the same catalyst prepared with magnetic stirring and conventional heating. The Ce-promoted silica sieves offered a suitable support for the controlled growth of nanocarbon that does not result in catalyst deactivation or poisoning after 6 h on stream.
