(569fv) Cobalt and CeO2 Modified Ni/Al2O3 Catalyst for Steam Reforming of Ethanol

The quest for renewable, cost-effective, and environment-friendly energy sources has become a focal point to academia and industry. Consumption of fossil fuels emits significant toxic gases causing serious environmental issues. This critical situation has motivated researchers to develop processes for alternative energy source like generation of hydrogen and its use as clean fuel. Hydrogen can be produced from renewable sources such as bioethanol by steam reforming, which is gaining serious attention in these days. Bioethanol is a biomass derived product, and theoretically 1 mole of ethanol can produce 6 moles of hydrogen. Ni-based catalysts are potentially good for this reaction, but the main disadvantages associated with such catalysts are poor stability at high temperature. Therefore, it is increasingly important to modify Ni based catalysts aiming for even better activity and improved stability. In present work, several Ni-Co bimetallic catalysts were prepared by varying Ce:Al ratio in the Al₂O₃-CeO₂ support. Additionally, characterization techniques such as, BET, EDS, H₂-TPR, pulse chemisorption, and temperature programmed oxidation were performed. The inclusion of Co in the Ni-Co bimetallic catalysts provides higher metal dispersion compared to monometallic Ni catalyst. Interestingly, modifying Al₂O₃ support by adding CeO₂ led stronger interaction of active species compared to Al₂O₃ only. The reforming reaction was conducted in a fixed bed reactor at atmospheric pressure; temperature of 650 ⁰C; steam/ethanol molar ratio of 8 and space time of 17.27 kg cat hr/kmol of ethanol. Figure 1 reveals that yield of hydrogen per mole ethanol is increased for Ni-Co catalysts. Moreover, among the catalysts tested, Ni-Co/Al₂O₃-CeO₂ (20wt% CeO₂) exhibited the best catalytic performance in terms of H₂ yield. The time-on-stream behavior of the best catalyst (10Ni5Co80Al20Ce) is reported in figure 2 showing stability of this catalyst under the chosen condition with suppressed formation of side products namely CO and CH₄.