Low temperature steam reforming of methanol over layered double hydroxide-derived catalysts

Abstract

The catalytic production of hydrogen by steam reforming of methanol (SRM) has been carried out over Mg/Al, Cu/Al, Co/Al, and Ni/Al layered double hydroxides (LDHs). The catalytic reactions were performed at temperatures of 150–400 °C and atmospheric pressure. The most efficient catalyst was the Cu/Al LDH, which became active at ∼230 °C, with concomitant H 2 production. The Ni/Al and Co/Al LDHs were also active in SRM, however, the activation temperature was significantly higher (315–320 °C). No catalytic activity was observed for the Mg/Al LDH. Significant LDH decomposition occurred during the catalytic reactions. The reducibility of the divalent cations present in the LDH was a crucial parameter in determining the steam reforming activity of the catalysts. Pre-activation of the Cu/Al LDH by calcination in air (400 °C), followed by reduction in dilute H 2, did not significantly change the catalytic activity. The onset of H 2 production was slightly lower for the pre-activated versus as-prepared Cu/Al LDH (∼218 °C), also the CH 3OH conversion was 5–10% lower.