Abstract
Cobalt-based catalysts using aluminum oxide as a support and 0.025-0.10 wt.% iridium as a second metal were prepared by the impregnation method and tested in steam and dry reforming of a model biogas with a ratio of CH4:CO2=1:1. The processes were carried out in a fixed bed flow reactor under atmospheric pressure, a gas hourly space velocity of 1000-1500 h-1, and temperature varied in the range of 300-800 ºC. The BET surface area, XRD, SEM, TEM, and H2-TPR methods were used to characterize the physicochemical properties of the “fresh” and “spent” samples of catalysts. The catalysts exhibit high and stable activity in the production of syngas from the biogas. Methane was almost completely converted at 750-800ºC in the steam reforming of biogas. Stability tests over 80-100 hours confirmed the catalyst's stable operation. Syngas with a ratio of H2/CO ~ 0.9 is formed in dry reforming of biogas, while in steam reforming the ratio exceeds 1. It is believed that the addition of iridium to Co/Al2O3 causes the improvement of the catalyst performance due to a synergetic effect because of the interaction between Co and Ir.