The activity of Rh/ZSM-5 catalysts for methane oxidation was investigated under conditions simulating the exhaust from lean burning, natural gas fueled engines to evaluate the influence of reaction atmosphere on catalytic activity. The Rh-catalysts yield high methane conversion at conditions achievable in real exhaust systems, despite the inhibiting effects of H₂O and SO₂. The influence of temperature and SO₂ concentration (1−20 ppm) on the activity were studied. The deactivation caused by SO₂ was intensified with decreasing temperature and increasing SO₂ concentration, and the SO₂-poisoning could be modeled as the occupation of active sites following a Temkin adsorption isotherm. At 400 °C essentially full coverage of S-species was reached with 1−2 ppm of SO₂, but at 500 °C the coverage had decreased significantly, and considerable catalytic activity was preserved in the presence of SO₂. Significant activity was regenerated in SO₂-free gas, but the nature of the SO₂-free regeneration atmosphere was unimportant.

在模拟稀燃天然气燃料发动机的废气条件下，研究了Rh / ZSM-5催化剂的甲烷氧化活性，以评估反应气氛对催化活性的影响。尽管有H ₂ O和SO ₂的抑制作用，但Rh催化剂在实际排气系统中可达到的条件下仍能产生较高的甲烷转化率。研究了温度和SO ₂浓度（1-20 ppm）对活性的影响。引起的SO减活₂是随着温度的降低和增加加剧SO ₂浓度，和SO ₂毒化可以建模为Temkin吸附等温线后活动位点的占用。在400°C下，1-2 ppm的SO ₂基本上达到了S物种的完全覆盖，但是在500°C下，该物种的覆盖率显着降低，并且在存在SO ₂的情况下保留了相当大的催化活性。在不含SO _2的气体中再生了显着的活性，但是不含SO _2的再生气氛的性质并不重要。