Low temperature steam reforming of ethanol over advanced carbon nanotube-based catalysts

Abstract

Steam reforming of biofuels such as bioethanol offers a clean and sustainable route to improve hydrogen production capacity for the hydrogen economy. In this work, the influence of the carbon support type (carbon nanotube [CNT], activated carbon [AC] and graphitic carbon black [GCB]) and the addition of Pt (1 wt.%, 1.5 wt.% and 2 wt.%) and ZnO (10 wt.%) to Ni10/CNT (10 wt.% Ni) are studied in steam reforming of ethanol (SRE) at low temperatures (≤450°C). The prepared CNT-based catalysts were characterized by nitrogen physisorption, X-ray powder diffraction (XRD), energy-dispersive X-ray (EDX) and energy filtered transmission electron microscopy (EFTEM) analyses. Ni supported on CNTs was found to be highly active for SRE compared to other conventional carbon supported catalysts. The promotional effect of Pt in the Ni10Ptx/CNT catalysts was found to be unexpectedly insignificant in terms of ethanol conversion, hydrogen production and selectivity. By contrast, the hybrid (ZnO)10Ni10/CNT catalyst showed superior catalytic performance below 450°C with high H2 selectivity and low CO selectivity compared to all other CNT-based catalysts. The Ni10/CNT catalyst undergoes rapid deactivation compared to the ZnO promoted Ni10/CNT due to the large amounts of carbon deposition on the catalyst. The ZnO promoted Ni10/CNT catalyst enhances the hydrogen production and reduces the carbon formation, making the catalyst attractive for the SRE reaction.

Keywords

• cnt
• hydrogen production
• ni
• zno