Hydrogen production by steam reforming of acetic acid using hydrotalcite type precursors

Acetic acid can be used as a model compound in the study of the steam reforming of the hydrophilic phase of bio-oil. In order to perform acetic acid reforming reactions, low cost catalysts with high catalytic activity and selectivity are required. Thus, NiMgAl hydrotalcite derived catalysts emerge as a good alternative. In this work, four NiMgAl hydrotalcite type precursors were prepared, with different Ni/Mg molar ratios (0.3, 0.4, 0.5, and 0.6). Various characterization tests have been performed for the prepared hydrotalcite type precursors. The stability of the catalytic activity was evaluated during 24 h and the used samples were submitted to a thermogravimetric analysis to evaluate carbon accumulation. Characterization tests proved that Ni/Mg ratios had a direct influence in the reducibility of the precursors. The Temperature-programmed surface reaction analysis showed that the steam reforming of acetic acid occurred majorly when the temperature reached 873 K. Stability test showed that precursors 04NiMg and 05NiMg had the best catalytic performance. It was also seen that sample 06NiMg suffered from deactivation by carbon deposition, which was confirmed by the thermogravimetric analysis.