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采用分步浸渍法制备了1%Pd-0.2%Pt/Al2O3和1%Pd-0.2%Pt-0.6%Ce/Al2O3催化剂,并基于固定床连续流动反应器,在空速为80000h-1的条件下,评价了催化剂的甲烷催化燃烧活性及其热稳定性.采用BET、CO化学吸附、XRD手段对催化剂进行了表征.结果表明,对应1%Pd-0.2%Pt/Al2O3和1%Pd-0.2%Pt-0.6%Ce/Al2O3催化剂的起燃温度(T50)分别为362℃和342℃;400℃下,甲烷转化率下降15%对应的反应时间分别为2.2h和24.5h.0.6%Ce的加入可显著提高1%Pd-0.2%Pt/Al2O3催化剂的活性及其热稳定性,这是因为Ce的存在提高了催化剂表面活性粒子PdO的分散度,并有效抑制了反应过程中PdO晶粒的长大.
1% Pd-0.2% Pt / Al 2 O 3 and 1% Pd-0.2% Pt-0.6% Ce / Al 2 O 3 catalyst were prepared by the step impregnation method. Based on the fixed bed continuous flow reactor, , The catalysts were evaluated for catalytic activity and thermal stability. The catalysts were characterized by BET, CO chemisorption and XRD. The results showed that the catalysts were characterized by 1% Pd-0.2% Pt / Al2O3 and 1% Pd-0.2 The ignition temperature (T50) of the Pt-0.6% Ce / Al2O3 catalyst were 362 ℃ and 342 ℃, respectively. At 400 ℃, the reaction time of methane conversion decreased 15% and 2.2h and 24.5h.0.6% Ce Addition can significantly improve the activity of 1% Pd-0.2% Pt / Al2O3 catalyst and its thermal stability, because the presence of Ce increases the PdO dispersion of the catalyst surface active particles and effectively inhibits the PdO crystal grains during the reaction grow up.