Study on CO selective oxidation over Ru-La-O/γ-Al_2O_3 and regeneration of catalyst in hydrogen-rich gas

Ru-La-O/γ-Al2O3 composite oxide catalysts with various La2O3 contents were prepared by two-step impregnation method,and the selective oxidation of CO in the hydrogen-rich gas over the prepared catalysts was studied in a fixedbed micro-reactor.The catalysts were characterized by means of TPR and XRD,and the effect of La2O3 loading and regeneration methods on the activity of catalysts were investigated.The results showed that high CO conversion (99%) and selectivity could be obtained in a wide temperature range of 110℃～170℃ over the catalysts with appropriate quantity of La2O3.The optimum catalyst was Ru1-La10-Oy/γ-Al2O3 with La mass fraction of 10%,and the deactivated catalyst could be regenerated to some extent by treating at 250℃ in nitrogen or 20% H2/N2 atmosphere,while it could be well regenerated in 20% O2/N2 at the same temperature,which was probably due to that the treatment in 20% O2/N2 atmosphere could increase the surface absorbed oxygen.