Production of syngas from steam reforming and CO removal with water gas shift reaction over nanosized Zr_(0.95)Ru_(0.05)O_(2-δ) solid solution

摘要

This study presents the synthesis, characterization, and kinetics of steam reforming of methane and water gas shift (WGS) reactions over highly active and coke resistant Zr_(0.95)Ru_(0.05)O_(2-δ). The catalyst showed high activity at low temperatures for both the reactions. For WGS reaction, 99% conversion of CO with 100% H_2 selectivity was observed below 290 ℃. The detailed kinetic studies including influence of gas phase product species, effect of temperature and catalyst loading on the reaction rates have been investigated. For the reforming reaction, the rate of reaction is first order in CH_4 concentration and independent of CO and H_2O concentration. This indicates that the adsorptive dissociation of CH_4 is the rate determining step. The catalyst also showed excellent coke resistance even under a stoichiometric steam/carbon ratio. A lack of CO methanation activity is an important finding of present study and this is attributed to the ionic nature of Ru species. The associative mechanism involving the surface formate as an intermediate was used to correlate experimental data.