Separation and Determination of Autocatalyst-Derived Platinum, Palladium, and Rhodium in the Environment

由于汽车配备三效催化剂(即同时脱除尾气中的一氧化碳、氮氧化物和碳氢化合物)，催化剂在400-1000℃的严格条件下运行，铂、钯和铑通过催化降解释放，造成环境污染。然后，对4种汽油动力车的排气管和消声器的烟尘中贵金属的排放进行了研究，确定了它们的值分别为：Pt11-32ppm，Pd7-19ppm，Rh：3-25ppm。这些贵金属的含量随着汽车在道路上行驶距离的增加(5万~13万公里)以及尾气管道中三效催化转化器的使用而增加。在碳烟样品中，大发汽车的烟尘样品中检测到了Pd和Rh，而在Familia(马自达)、Sunny(日产)和Skyline(日产)的烟尘样品中分别检测到了铂和Rh。检测到烟尘…中除贵金属外的无机成分(10.7-5,440 ppm)天际线(跑步距离：13万公里，1992年类型)多为Na、Ca、Fe、Zn&Gt；Al&Gt；Si&Gt；Mg、Mn、Ni&Gt；Ce&Gt；V、Zr等，而Ba、Co、La、Mo等元素在检测范围内。主要道路(国道、8号线、今井、金泽)、Pd(29-59 ppb)和Rh(15-34 ppb)在汽车道路白线边缘1米范围内检出，而铂低于检测限值(8 Ppb)。这一结果表明，这些从机动车排放的珍贵金属颗粒相对较重，不会远离汽车排气管，在道路边缘坠落。在隧道的道路上(国道、157线、东福口和科威特岛，靠近Tedori大坝的石川市)，在距土壤和内壁烟尘1米的范围内检测到Pd(26-84 ppb)和Rh(230-1,700 ppb)，而铂在检测下限(8 Ppb)以下。用0.1M盐酸从排气管和消声器的烟尘中检测到Pd和Rh的溶解度为1%，而没有观察到铂的溶解度。这一结果表明，少量的Pd和Rh以氯化物的形式存在。较少

Since automobiles equipped with three-way (i.e. removing carbon monoxide, nitrogen oxides, and hydrocarbons together in exhaust gasses) catalysts run under strict conditions as 400-1000 ℃, platinum, palladium, and rhodium are released by catalytic degradation, causing an environmental pollution. Then, the emissions of these precious metals in soot from the exhaust pipes and mufflers of 4 types of gasoline powered cars, were investigated first and ascertained that the values were Pt : 11-32 ppm, Pd : 7-19 ppm, and Rh : 3-25 ppm, respectively. The content of these precious metals tends to increase with increasing the running distance (50,000-130,000 km) of cars in roads, and also with drawing to the three-way catalytic converter in exhaust pipes.In soot samples, Pd and Rh were detected in M IRA (DAIHATSU), while Pt and Rh were detected in FAMILIA (MAZDA), SUNNY (NISSAN), and SKYLINE (NISSAN), respectively. Inorganic ingredient (10.7-5,440 ppm) detected except for precious metals in soot … More of SKYLINE (running distance : 130,000km, 1992 type) were Na, Ca, Fe, Zn>Al>Si>Mg, Mn, Ni>Ce>V, Zr, etc, while Ba, Co, La, and Mo were under detection limit.In environmental samples involving soot of cars and dusts, as soil and moss (Bryum argenteum Hedw.) in major road ways (national road, the 8 line, Imamaehi, Kanazawa), Pd (29-59 ppb) and Rh (15-34 ppb) were detected within 1m from the edge of the white line of automobile road, while Pt were under detection limit (<8ppb). This results indicate that these precious metalt particles emitted from motor vehicles are relatively heavy, and don't travel far from car exhaust pipes, falling out at the edges of roadways. In road ways of tunnel (national road, the 157 line, Higashifutaguchi and Kuwajima, near Tedori dam, Ishikawa), Pd (26-84 ppb) and Rh (230-1,700 ppb) were detected within 1 m from soil and soot of the inside wall, while Pt was under detection limit (8 ppb).Solubility of Pd and Rh in soot from the exhaust pipe and mufflers using 0.1 M hydrochloric acid were <1%, while that of Pt was not observed. This result suggests that a small amount of Pd and Rh is in chloride species. Less