PLAPIQUI   05457
PLANTA PILOTO DE INGENIERIA QUIMICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
CO removal at the microscale: a 1-cent gold PrOx reactor
Autor/es:
N. JIMÉNEZ; E. LÓPEZ; T. TRIFONOV; A. RODRIGUEZ; J. LLORCA
Reunión:
Conferencia; XIX International Conference on Chemical Reactors; 2010
Resumen:
A
silicon micromonolith containing ca. 40000 regular channels of 3.3 mm
in diameter per square millimeter has been successfully functionalized with an
Au/TiO2 catalyst for CO preferential oxidation (CO-PrOx) in the
presence of hydrogen. The functionalization of the silicon microchannels has
been accomplished by growing a SiO2 layer on the channel walls,
followed by exchange with a titanium alkoxyde precursor and decomposition into
TiO2 and, finally, by anchoring carbosilanethiol dendron protected pre-formed
Au nanoparticles. Catalytically active centers at the Au-TiO2
interface have been obtained by thermal activation. With this method, an
excellent homogeneity and adherence of the catalytic layer over the
microchannels of the silicon micromonolith has been obtained, resulting in
geometric exposed surface area values of about 4x105 m2/m3.
The functionalized silicon micromonolith has been tested for CO-PrOx at 363-433
K and l=2 under H2/CO=0-20
(molar), and the results have been compared with those obtained over a
conventional cordierite monolith with 400 cpsi loaded with the same catalyst. The
performance of the silicon micromonolith, which converts ca. 1 NmL of CO per
minute and mL of microreactor at 398 K under H2/CO~20, is two
orders of magnitude higher than that of conventional monolithic
structures, suggesting that silicon micromonoliths could be particularly effective
for hydrogen purification in low-temperature microfuel cells for portable
applications.