Fabrication and characterization of a fuel flexible micro-reformer fully integrated in silicon for micro-solid oxide fuel cell applications

A novel design of a fuel-flexible micro-reactor for hydrogen generation from ethanol and methane is proposed in this work. The micro-reactor is fully fabricated with mainstream MEMS technology and consists of an array of more than 20000 through-silicon vertically aligned micro-channels per cm2 of 50 μm in diameter. Due to this unique configuration, the micro-reformer presents a total surface per projected area of 16 cm2/cm2 and per volume of 320 cm2/cm3. The active surface of the micro-reformer, i.e. the walls of the micro-channels, is homogenously coated with a thin film of Rh- Pd/CeO2 catalyst. Excellent steam reforming of ethanol and dry reforming of methane are presented with hydrogen production rates above 3 mL/min·cm2 and hydrogen selectivity of ca. 50% on a dry basis at operations conditions suitable for application in micro-solid oxide fuel cells (micro-SOFCs), i.e. 700-800ºC and fuel flows of 0.02 mLL/min for ethanol and 36 mLG/min for methane (corresponding to a system able to produce one electrical watt).

[1]  J. Llorca,et al.  A million-channel reformer on a fingertip: Moving down the scale in hydrogen production , 2010 .

[2]  J. Martynczuk,et al.  Micro‐Solid Oxide Fuel Cell Membranes Prepared by Aerosol‐Assisted Chemical Vapor Deposition , 2014 .

[3]  L. F. Brown.  A comparative study of fuels for on-board hydrogen production for fuel-cell-powered automobiles , 2001 .

[4]  F. Prinz,et al.  Three-dimensional nanostructured bilayer solid oxide fuel cell with 1.3 W/cm(2) at 450 °C. , 2013, Nano letters.

[5]  Fritz B. Prinz,et al.  High-Performance Ultrathin Solid Oxide Fuel Cells for Low-Temperature Operation , 2007 .

[6]  N. Sabaté,et al.  Porous La0.6Sr0.4CoO3−δ thin film cathodes for large area micro solid oxide fuel cell power generators , 2014 .

[7]  Alejandro J. Santis-Alvarez,et al.  A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional micro- fluidic carrier , 2014 .

[8]  Carles Cané,et al.  Electrical characterization of thermomechanically stable YSZ membranes for micro solid oxide fuel cells applications , 2010 .

[9]  Bo-Kuai Lai,et al.  Scalable nanostructured membranes for solid-oxide fuel cells. , 2011, Nature nanotechnology.

[10]  D. Borio,et al.  Ethanol steam reforming for hydrogen generation over structured catalysts , 2013 .

[11]  Jennifer L. M. Rupp,et al.  Review on microfabricated micro-solid oxide fuel cell membranes , 2009 .

[12]  I. Gràcia,et al.  Pinhole-free YSZ self-supported membranes for micro solid oxide fuel cell applications , 2012 .

[13]  V. Hessel,et al.  Ethanol Steam Reforming in a Microchannel Reactor , 2007 .

[14]  Yves Schuurman,et al.  Hydrogen production from ethanol steam reforming in a micro-channel reactor , 2010 .

[15]  Carles Cané,et al.  Residual stress of free-standing membranes of yttria-stabilized zirconia for micro solid oxide fuel cell applications. , 2010, Journal of nanoscience and nanotechnology.

[16]  Alejandro J. Santis-Alvarez,et al.  Syngas Generation from N-butane with an Integrated Mems Assembly for Gas Processing in Micro-solid Oxide Fuel Cell Systems , 2022 .

[17]  C. Sandu,et al.  Nanoporous YSZ film in electrolyte membrane of Micro-Solid Oxide Fuel Cell , 2010 .

[18]  S. Ramanathan,et al.  Nanoscale Compositionally Graded Thin‐Film Electrolyte Membranes for Low‐Temperature Solid Oxide Fuel Cells , 2012 .

[19]  Alejandro J. Santis-Alvarez,et al.  Comparison of flame-made rhodium on Al2O3 or Ce0.5Zr0.5O2 supports for the partial oxidation of methane , 2014 .

[20]  Robert E. Rettew,et al.  A phenomenological study of the metal-oxide interface: the role of catalysis in hydrogen production from renewable resources. , 2008, ChemSusChem.

[21]  A. Serrano-Lotina,et al.  Influence of the operating parameters over dry reforming of methane to syngas , 2014 .

[22]  R. Alcubilla,et al.  First use of macroporous silicon loaded with catalyst film for a chemical reaction: a microreformer for producing hydrogen from ethanol steam reforming , 2008 .

[23]  J. Llorca,et al.  Autothermal generation of hydrogen from ethanol in a microreactor , 2008 .

[24]  James Spivey,et al.  A review of dry (CO2) reforming of methane over noble metal catalysts. , 2014, Chemical Society reviews.

[25]  Alejandro J. Santis-Alvarez,et al.  A nanoparticle bed micro-reactor with high syngas yield for moderate temperature micro-scale SOFC power plants , 2012 .

[26]  J. Martynczuk,et al.  Integration of Spin‐Coated Nanoparticulate‐Based La0.6Sr0.4CoO3–δ Cathodes into Micro‐Solid Oxide Fuel Cell Membranes , 2013 .

[27]  Eduardo López,et al.  Bio-ethanol steam reforming and autothermal reforming in 3-μm channels coated with RhPd/CeO2 for hydrogen generation , 2013 .

[28]  J. Lercher,et al.  Mono and bifunctional pathways of CO2/CH4 reforming over Pt and Rh based catalysts , 1998 .

[29]  Luis Fonseca,et al.  Full ceramic micro solid oxide fuel cells: towards more reliable MEMS power generators operating at high temperatures , 2014 .

[30]  P. Muralt,et al.  Solid oxide fuel cell membranes supported by nickel grid anode , 2008 .

[31]  F. Prinz,et al.  Solid oxide fuel cell with corrugated thin film electrolyte. , 2008, Nano letters.