The current problem of the depletion of fossil-fuel reserves, call for new energy systems based on renewable fuels. Hydrogen, a clean fuel, is in growing demand due to the technological advancements made in the fuel cell industry. The ultimate objective of this project is to be able to feed the H2 rich and CO free gas directly to PEM fuel cell, without the expense of intermediate gas cleaning or upgrading (CO removing), which was approached by the development of efficient and low cost catalysts.
Firstly, a series of Pt catalysts supported on alumina that was doped with different amounts of CeO2 were developed, characterized and tested in the aqueous-phase reforming (APR) of glycerol to H2. Several parameters like pressure, temperature, feed concentration and feed flow rate were optimized. No CO could be detected (< 100 ppm) in the product gas, meaning that the product may be directly useable in a PEM fuel cell.
Secondly, bimetallic Pt-Ni supported on 3 wt% CeO2-doped Al2O3 (3CeAl) and multi-walled carbon nanotubes (MWNT) were studied. XRD, XPS and STEM-EDS analysis shows the evidence of Pt–Ni interaction which is thought to be responsible for their higher activity and selectivity in APR. A bimetallic catalyst – 1 wt% Pt and 3 wt% Ni supported on MWNT was then identified the best one compared to commercial Pt/Al2O3
Lastly, amongst the non-noble based Cu-Ni alloy catalysts tested, bimetallic 1Cu–12Ni/MWNT catalyst gave the higher H2 selectivity (86%) and glycerol conversion (84%). Though 1Cu–12Ni/MWNT catalyst showed slightly lower H2 selectivity (86%) than the 1Pt-3Ni/MWNT catalyst (H2 selectivity 91%), but the former is much cheaper compare to highly expensive Pt catalyst. This measure is crucial to the competitiveness of a catalyst in large-scale H2 production.