Hydrogen production from the steam reforming of methane over Ni supported on ZSM-5 zeolite catalysts

Abstract

The catalytic reforming of methane with steam is the most widely used process for syngas production. Nevertheless, development of the reforming catalyst is required to reduce the risks of catalytic deactivation caused by carbon deposition and/or sintering of the metal crystallites. In this research, the catalytic performance of Ni/ZSM-5 zeolite catalysts prepared by impregnation was investigated at 700°C under atmospheric pressure with various steam/carbon ratios of 0.8, 1, and 2. The effects of metal loading and CeO2 addition were studied in terms of catalytic activity, selectivity, and carbon deposition. Both fresh and spent catalysts were characterized by using ICP, XRD, TGA, TEM, and TPO techniques, which revealed that the 11%Ni/5%Ce/ZSM-5 catalyst at a steam/carbon ratio of 0.8 showed the highest catalytic activity and carbon resistance with an initial methane conversion of 99.45%, and a hydrogen selectivity of 52.93%. It was found that the addition of a CeO2 promoter decreased the deactivation rate of the catalyst; however, at a high loading of CeO2, high coke formation was clearly observed by XRD, TGA, TEM, and TPO. The 11%Ni/5%Ce/ZSM-5 catalyst exhibited high catalytic stability for 12 hours time-on-stream.