Steam reforming of ethanol to H2 over Rh/Y2O3: crucial roles of Y2O3 oxidizing ability, space velocity, and H2/C

Abstract

Rh/Y₂O₃ is found to produce the highest rate of hydrogen in steam reforming of ethanol (SRE) at a high reaction temperature of 650–800 °C, with the order of catalyst activity as follows: Rh/Y₂O₃ > Rh/CeO₂ > Rh/La₂O₃ > Rh/Al₂O₃. The activity of Rh/Y₂O₃ was significantly promoted due to the strong oxidizing ability of Y₂O₃ to oxidize the hydrogen of ethanol to form hydrogen gas. The optimal gas hourly space velocity (GHSV) of 105 000 h⁻¹ at 700 °C produced the maximum H₂/CO molar ratio and the highest hydrogen production rate. The catalyst efficiency in converting ethanol is directly reflected by H₂/C, which is a new indicator established for the first time and can be used to achieve the highest hydrogen production rate at the lowest carbon emission.