Synthesis and characterization of non-noble nanocatalysts for hydrogen production in microreactors

Nanoscale Co and Ni catalysts in silica were synthesized using sol–gel method for hydrogen production from steam reforming of methanol (SRM) in silicon microreactors with 50 μm channels. Silica sol–gel support with porous structure gives specific surface area of 452.35 m² g⁻¹ for Ni/SiO₂ and 337.72 m² g⁻¹ for Co/SiO₂. TEM images show the particles size of Ni and Co catalysts to be <10 nm. The EDX results indicate Co and Ni loadings of 5–6 wt.% in silica which is lower than the intended loading of 12 wt.%. The DTA and XRD data suggest that 450 °C is an optimum temperature for catalyst calcination when most of the metal hydroxides are converted to metal oxides without significant particle aggregation to form larger crystallites. SRM reactions show 53% methanol conversion with 74% hydrogen selectivity at 5 μL min⁻¹ and 200 °C for Ni/SiO₂ catalyst, which is higher than that for Co/SiO₂. The activity of the metal catalysts decrease significantly after SRM reactions over 10 h, and it is consistent with the magnetization (VSM) results indicating that ∼90% of Co and ∼85% of Ni become non-ferromagnetic after 10 h.