Monolithic supports based on biomorphic SiC for the catalytic combustion of hydrogen
|Arzac, G. M.
Ramírez Rico, Joaquín
Gutierrez Pardo, Antonio Anselmo
Jiménez de Haro, María del Carmen
Martínez Fernández, Julián
Fernández Camacho, Alejandro
|Universidad de Sevilla. Departamento de Física de la Materia Condensada
Instituto de Ciencia de Materiales de Sevilla (ICMS) – CIC Cartuja
|Catalytic hydrogen combustion was studied with H2/air mixtures in conditions that simulate the H2 concentration of the exhaust gases from fuel cells (3–4% v/v H2 in air). Pt-impregnated monoliths based on porous biomorphic ...
Catalytic hydrogen combustion was studied with H2/air mixtures in conditions that simulate the H2 concentration of the exhaust gases from fuel cells (3–4% v/v H2 in air). Pt-impregnated monoliths based on porous biomorphic SiC (bio-SiC) substrates were employed for the first time for this reaction. Capillary forces were exploited for the incipient impregnation of supports with H2PtCl6 solutions. Freeze drying permitted us to obtain a homogeneous distribution of the active phase reducing accumulation at the monolith's outer shell. The supports and catalysts were characterized from a structural and thermal point of view. Catalytic tests were performed in a homemade reactor fed with up to 1000 ml min 1 H2/air mixtures and a diffusional regime (non-isothermal) was achieved in the selected conditions. Catalyst loading was tested in the range of 0.25–1.5 wt% Pt and 100% conversion was achieved in all cases. Temperatures were recorded at different points of the monoliths during the reaction showing anisotropic thermal behavior for selected bio-SiC substrates. These effects are of interest for heat management applications and were explained in correlation with thermal conductivity measurements performed on the supports. Pt-impregnated monoliths were also tested in less than 100% conversion conditions (1% v/v H2 in air) and in powder form in kinetic conditions for comparative purposes
|Arzac, G.M., Ramírez Rico, J., Gutierrez Pardo, A.A., Jiménez de Haro, M.C., Hufschmidt, D., Martínez Fernández, J. y Fernández Camacho, A. (2016). Monolithic supports based on biomorphic SiC for the catalytic combustion of hydrogen. RSC Advances, 6, 1-12.