Carbon supported catalysts in low temperature steam reforming of ethanol: study of catalyst performance

Three different metals (Pt, Pd and Ni) on multi-walled carbon nanotube and graphite supports were tested as catalysts in ethanol reforming experiments at low temperatures. The carbon nanotube based catalysts outperformed their counterparts supported on graphite in both ethanol conversion and hydrogen evolution. The palladium catalyst in both supports was rather inactive, whereas the nickel/nickel oxide catalyst showed excellent performance. The most active catalyst (Ni/CNT) showed ethanol conversion and hydrogen evolution already at 200 °C with complete conversion at 450 °C. The measured selectivity for H₂ production was ∼42% with almost 100% conversion. Analysis of the spent catalyst samples revealed a considerable increase in carbon concentration caused by the formation of soot and coke on each sample but also carbon nanofibers and nanotubes were found to grow on the catalyst nanoparticles in the course of the steam reforming reactions.