摘要
在固定床流动反应器中用程序升温反应(TPR)研究了SO_2对模拟柴油机排气中HC和CO在新鲜Pt催化剂和400℃硫化Pt催化剂作用下的催化氧化行为的影响。结果表明,反应气中的SO_2阻碍新鲜Pt催化剂对HC和CO的催化氧化,而硫化催化剂对C_3H_8的催化转化有促进作用。SO_2及其氧化产物SO_3在催化剂表面的化学吸附导致新鲜催化剂对HC和CO的催化性能下降,Pt催化剂和涂层载体γ-Al_2O_3界面的硫化物种在400℃下能够促进C_3H_8的催化氧化。
The effect of SO_2 on the catalytic oxidation behavior of HC and CO in simulating diesel exhaust was studied over fresh
and 400℃ sulfated 2. 5g/L Pt/γ-Al_2O_3 using a fixed-bed flow reactor with temperature programmed reaction(TPR). The results
showed that the inhibiting effect of SO_2 in the feed gas on the oxidation of HC and CO over fresh Pt/-Al_2O_3 as a result of SO_2 ad-
sorbed species formed on the surface of catalyst; the promoting effect of SO_2 on conversion of C_3H_6 over sulfated Pt/γ-Al_2O_3 be-
cause the SO_2 adsorbed species were oxidized to sulfate species on the Pt and γ-Al_2O_3 interface which strongly promote C_3H_8 oxi-
dation. SO_2 in the automotive exhaust presents inhibiting effect over Pt catalytic converters at present, however. the results showed
in this study tell us that SO_2 pretreatment at 400℃ might promote the C_3H_8 oxidation in the diesel exhaust.
出处
《内燃机》
2004年第3期17-20,共4页
Internal Combustion Engines
