Deactivation study of the BICOVOX catalysts used in low temperature steam reforming of ethanol for H2 production

Abstract

The γ-BICOVOX, having high O2- mobility at low temperature (≤300 °C), might be a good catalyst for hydrogen production by low temperature steam reforming (LTSR) of ethanol. LTSR (at atmospheric pressure) of ethanol over Bi4(V0.90Co0.10)2O11-δ (BICOVOX) catalysts (synthesized by a solution combustion method and calcined at 400, 600 and 800 °C) has been investigated at the reaction conditions of 400 °C, H2O: EtOH molar ratio 23:1 and 0.35 ml min−1 feed flow rate. Catalysts remain active for the time period of ~30 h and after that start to deactivate. According to the XRD analysis γ- BICOVOX decomposes to BiVO4, Bi2O3, and Bi phases due to a reducing environment present inside the reactor. According to the XPS analysis, decrease in γ- BICOVOX amount diminishes the oxygen vacancy in the lattice. This probably causes significant decline in O2- mobility through the lattice and consequently carbon deposition occurs (derived from XPS, FESEM & DTGA) leading to an almost complete deactivation of the catalysts within 150 h.