高比表面积Pd纤维催化剂的制备及其甲烷催化燃烧性能

Preparation of Pd fiber catalyst with high specific area and its catalytic performance for methane combustion

制备了PdO/CeO_2/γ-Al_2O_3/Al_2O_3-SiO_2纤维催化剂,考察了CeO_2掺杂对催化剂甲烷催化燃烧活性的影响。结果表明,掺杂质量分数O.05%CeO_2,催化剂活性最好,甲烷完全转化温度为385℃。BET比表面积测定结果显示,γ-Al_2O_3的加入极大提高了纤维的比表面积;氧气程序升温脱附实验结果表明,加入适量CeO_2,提高了活性相PdO的分解温度,从而提高了催化剂热稳定性。对制备的催化剂进行了实用性能(催化无焰燃烧器)考察,表明产品高效节能(燃气转化率为99%)、减排环保(CO含量小于10×10^(-6),未检测到NOx)和持久耐用(100 h保持高活性)。

PdO/CeO2/γ-Al2O3/Al2O3-SiO2 fiber catalysts were prepared and the influence of CeO2 on its activity for methane combustion was investigated. The results showed that the catalyst doped with 0.05wt% CeO2 exhibited the best catalytic activity and the complete oxidation temperature of methane was 385 ℃. Specific area of ceramic fibers was increased obviously by adding γ-Al2O3. The decomposition temperature of active phase PdO and thermal stability of the fiber catalyst were increased with adding CeO2. The performance of catalytic flameless heater was investigated using PdO/CeO2/γ-Al2O3/Al2O3-SiO2 as the catalyst. The catalytic flameless heater possessed the properties of high efficiency, energy saving, low emission and environmental protection. Methane conversion was over 99%, and the exhaust gas contained 10 × 10-6 CO and no NOx. The catalyst kept high activity during running for 100 h.