用于降低卷烟烟气中CO含量的Pd-Cu/活性炭催化剂

Pd-Cu/activated carbon catalyst for the oxidation of carbon monoxide in cigarette smoke

用浸渍法制备用于降低卷烟烟气中CO含量的Pd-Cu/活性炭催化剂,考察该催化剂对模拟卷烟烟气[4.4%CO-4.2%H_2O-19.2%O_2-72.2%N_2(体积分数)]中的CO常温催化氧化性能,研究催化剂活性组分及其负载量、催化剂载体、原料气中CO浓度和气体空速对催化剂的CO常温氧化活性的影响。研究表明,生产成本较低的1.4%Pd-3.9%Cu/活性炭催化剂的CO常温氧化活性较好,在气体空速20 000 h^(-1)和反应温度30℃条件下,对模拟卷烟烟气中的CO转化率可达46.8%。Pd-Cu/活性炭催化剂对CO的常温氧化活性随着Pd负载量的增加而增加,当Pd负载质量分数大于1.7%时,催化剂活性趋于稳定,如果同时改变Pd和Cu的负载量,对催化活性产生的影响比单一活性组分改变时产生的影响大。活性炭载体种类和原料气中CO浓度对CO常温催化氧化活性影响较大,以进口活性炭为载体制备的催化剂活性最好,气体空速和活性炭颗粒尺寸对催化剂活性影响较小。

Pd-Cu/activated carbon catalyst for the oxidation of carbon monoxide in cigarette smoke was prepared by wetness impregnation method.The effects of the active components and their loading,catalyst support,CO concentration and space velocity of the feed gas on the activity of the catalyst for catalytic oxidation of carbon monoxide at room temperature were investigated.The results showed that 1.4%Pd-3.9%Cu/activated carbon catalyst exhibited better catalytic activity for CO oxidation at room temperature and CO conversion of 46.8% at room temperature over the catalyst was attained under the reaction condition as follows：reaction temperature 30 ℃,space velocity 20 000 h-1 and simulated cigarette smoke [4.4%CO-4.2%H2O-19.2%O2-72.2%N2（volume fraction）] as the feed gas.The catalytic activity of CO oxidation over the catalyst at room temperature enhanced with the increase of Pd loading and then remained unchanged when Pd loading was over 1.7%（mass fraction）.The effects of change of Pd and Cu loading simultaneously were greater than that of change of Pd or Cu loading only.The kinds of the activated carbon support and CO concentration in the feed gas had great influence on the room-temperature catalytic oxidation activity of CO.The catalyst prepared with import activated carbon exhibited the best activity.However,space velocity of the feed gas and the particle size of the activated carbon had little influence.