• 关键词：钙钛矿  催化剂  催化燃烧  排放控制  天然气发动机  喷雾热分解

• 基金项目：国家自然科学基金项目（No.50376021，50776042）；河南省科技厅重点攻关计划项目（No.112102210363）

• 胡明江
• 河南城建学院能源与建筑环境工程学院, 平顶山 467036

• 王忠
• 江苏大学汽车与交通工程学院, 镇江 212013

• 摘要：采用喷雾热分解法制备了钙钛矿型催化剂La_0.7Sr_0.3Mn_1-xCo_xO_3-δ（x=0、0.3、0.5、0.7），利用 X 射线衍射（XRD）和扫描电子显微镜（SEM）对催化剂进行了表征，在微型固定床反应器上优化了催化剂的B位掺杂Co.在天然气发动机排放试验台架上进行了空燃比特性、CH₄排放和发动机尾气排放达标等测试试验.结果表明：在La_0.7Sr_0.3Mn_1-xCo_xO_3-δ中掺杂适宜量的Co有助于提高催化剂的催化燃烧活性，改善催化剂比表面积和孔容积.当Co掺杂量为0.5时，所形成的La_0.7Sr_0.3Mn_0.5Co_0.5O_3-δ催化剂对天然气发动机尾气排放物呈现出良好低温催化燃烧活性，对甲烷催化燃烧的起燃温度（T₁₀）、半转化温度（T₅₀）和完全转化温度（T₉₀）分别为175、350和400℃，CO、NO_x、非甲烷碳氢化合物（NMHC）和CH₄的最大比排放量分别为3.01、1.72、0.31和0.85 g·kW^-1·h^-1，达到了国Ⅴ排放法规对天然气发动机有害排放物的限值要求，表明了La_0.7Sr_0.3Mn_0.5Co_0.5O_3-δ适宜用于天然气发动机尾气低温催化燃烧的催化剂.

• Abstract：Perovskite-type La_0.7Sr_0.3Mn_1-xCo_xO_3-δ(x=0,0.3,0.5,0.7)catalysts were prepared by spray pyrolysis method, and the catalysts were characterized by using X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The catalysts performances were optimized in a micro fixed-bed reactor through doping appropriate amount of Co into B sites of La_0.7Sr_0.3Mn_1-xCo_xO_3-δ. The characteristic tests, including the air-fuel ratio, methane emissions and the emission standards, were carried out on emission test bench of natural gas engine. The results showed that the catalytic combustion activity of La_0.7Sr_0.3Mn_1-xCo_xO_3-δ was improved through doping appropriate amount of Co, and the specific surface area and pore volume of catalysts increased accordingly. When doping amount of Co was 0.5, the resultant La_0.7Sr_0.3Mn_0.5Co_0.5O_3-δ presented good low-temperature catalytic combustion activity for methane, with its catalytic combustion parameters on light-off temperature (T₁₀), half conversion temperature (T₅₀) and total conversion temperature (T₉₀) were 175℃, 350℃ and 400℃, respectively. The largest specific emissions of CO, NO_x, Non-methane hydrocarbons(NMHC) and methane were separately 3.01,1.72, 0.31 and 0.85 g·kW^-1·h^-1, which met the national V emissions regulations about emission limited criterion for natural gas engine. Therefore, it is concluded that La_0.7Sr_0.3Mn_0.5Co_0.5O_3-δ had the best low-temperature catalytic combustion activity for emission of natural gas engine.

• Key words：perovskite  catalysts  catalytic combustion  emission control  natural gas engine  spray pyrolysis process

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