Steam reforming of ethanol on Rh/SiCeO2 washcoated monolith catalyst: Stable catalyst performance

Abstract

The performance of a new Rh/CeSiO2 catalyst supported on a ceramic monolith for steam reforming (SR) of ethanol for hydrogen generation was investigated. It provides several advantages over a traditional pellet based catalyst in that it will reduce weight, size and pressure drop in the reactor. The effect of steam to ethanol molar ratio and temperature were first investigated on a powdered catalyst in order to establish the preferred reaction conditions to be used for tests on the monolith. The optimum temperature for coke free, high selectivity and stable catalyst operation was 1073 K at a steam to ethanol molar ratio of 3.5. The monolith supported catalyst was evaluated for aging stability, on/off performance and coke regeneration using steam gasification. After 96 h of SR of ethanol at 1028 K and water/ethanol molar ratio of 3.5 the monolith supported catalyst retained stable performance throughout the entire time on stream with the only products being H2, CO, CO2. Some coke formation was observed using Raman spectra, however, it did not cause any permanent deactivation. Regeneration via steam gasification at 973 K with 20% steam in N2 was successful for coke removal and complete catalyst regeneration.