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

The gamma-BICOVOX, having high O2- mobility at low temperature (<= 300 degrees C), might be a good catalyst for hydrogen production by low temperature steam reforming (LTSR) of ethanol. LTSR (at atmospheric pressure) of ethanol over Bi-4(V0.90Co0.10)(2)O11-delta (BICOVOX) catalysts (synthesized by a solution combustion method and calcined at 400, 600 and 800 degrees C) has been investigated at the reaction conditions of 400 degrees C, H2O: EtOH molar ratio 23:1 and 0.35 ml min(-1) feed flow rate. Catalysts remain active for the time period of similar to 30 h and after that start to deactivate. According to the XRD analysis gamma-BICOVOX decomposes to BiVO4, Bi2O3, and Bi phases due to a reducing environment present inside the reactor. According to the XPS analysis, decrease in gamma-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.

Automated summary

The study examined the performance of gamma-BICOVOX as a catalyst at low temperatures, finding that as the activity time of the catalyst increased, a decrease in oxygen vacancies led to reduced oxygen mobility, eventually causing almost complete deactivation of the catalyst within 150 hours.