Combined CO/CH₄ oxidation tests over Pd/Co₃O₄ monolithic catalyst: Effects of high reaction temperature and SO₂ exposure on the deactivation process

详细信息	查看全文 | 推荐本文 |

• 作者：L.F. Liotta ; G. Di Carlo ; G. Pantaleo ; A.M. Venezia ; G. Deganello ; E. Merlone Borla ; M. Pidria
• 关键词：Pd/Co₃O₄ monolith ; CO and CH₄ oxidation ; PdO and Co₃O₄ thermal stability ; SO₂ poisoning
• 刊名：Applied Catalysis B ; Environmental
• 出版年：2007
• 期刊代码：4_09263373
• 类别：ce
• 出版时间：26 September 2007
• 卷：75
• 期：3-4
• 页码：182-188
• 文件大小：1001 K

摘要

CO and CH₄ combined oxidation tests were performed over a Pd (70 g/ft³)/Co₃O₄ monolithic catalyst in conditions of GHSV = 100,000 h⁻¹ and feed composition close to that of emission from bi-fuel vehicles. The effect of SO₂ (5 ppm) on CO and CH₄ oxidation activity under lean condition (λ = 2) was investigated. The presence of sulphur strongly deactivated the catalyst towards methane oxidation, while the poisoning effect was less drastic in the oxidation of CO. Saturation of the Pd/Co₃O₄ catalytic sites via chemisorbed SO₃ and/or sulphates occurred upon exposure to SO₂. A treatment of regeneration to remove sulphate species was attempted by performing a heating/cooling cycle up to 900 °C in oxidizing atmosphere. Decomposition of PdO and Co₃O₄ phases at high temperature, above 750 °C, was observed. Moreover, sintering of Pd⁰ and PdO particles along with of CoO crystallites takes place.