硫酸氢钾熔融-电感耦合等离子体原子发射光谱法测定废铑氧化铝催化剂中铑

废铑氧化铝催化剂中含有大量铑元素,回收催化剂中铑元素可以降低生产成本,因此准确测定废铑氧化铝催化剂中铑元素含量至关重要。然而废铑氧化铝催化剂组成复杂,常规湿法消解和微波消解方法无法完全溶解样品。实验采用0.1g废铑氧化铝催化剂和3.0g硫酸氢钾在650℃下熔融4h,熔融物使用10mL 10%(体积分数)硫酸加热溶解,然后使用电感耦合等离子体原子发射光谱法(ICP-AES)测定铑,建立了熔融-电感耦合等离子体原子发射光谱法测定废铑氧化铝催化剂中铑的方法。ICP-AES工作条件为射频(RF)功率1.20kW、雾化气流量0.85L/min。校准曲线的线性相关系数R²=0.9999;方法检出限为0.01mg/L,测定下限为0.1mg/L。按照实验方法测定两个废铑氧化铝催化剂中铑,测定结果的相对标准偏差(RSD,n=9)为0.52%~0.56%;加标回收率为99.6%~100.3%。实验方法用于测定两个废铑氧化铝催化剂模拟样品中铑,测定值和理论值相一致。

Determination of rhodium in waste rhodium-aluminum oxide catalyst by inductively coupled plasma atomic emission spectrometry with potassium hydrogen sulfate fusion

The waste rhodium-aluminum oxide catalyst contains much rhodium. The recovery of rhodium from catalyst can reduce the production cost. Therefore, the accurate determination of rhodium content in waste rhodium-aluminum oxide catalyst is of great importance. However, the composition of waste rhodium-aluminum oxide catalyst is very complicated, and the sample cannot be completely dissolved by conventional wet digestion and microwave digestion methods. In proposed study, 0.1g of waste rhodium-aluminum oxide catalyst and 3.0g of potassium hydrogen sulfate were fused at 650℃ for 4h. The melt was dissolved with 10mL of 10% (volume fraction) sulfuric acid under heating. Then, the content of rhodium in sample solution was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The determination method of rhodium in waste rhodium-aluminum oxide catalyst by ICP-AES after fusion was established. The working conditions of ICP-AES were listed as follows: the radio frequency (RF) power was 1.20kW and the atomizing gas flow rate was 0.85L/min. The linear correlation coefficient of calibration curve was R²=0.9999. The detection limit was 0.01mg/L and the low limit of determination was 0.1mg/L. The content of rhodium in two waste rhodium-aluminum oxide catalyst samples was determined according to the experimental method. The relative standard deviation (RSD, n=9) of determination results was in range of 0.52%-0.56%. The recoveries were between 99.6% and 100.3%. The content of rhodium in two simulation samples of waste rhodium-aluminum oxide catalyst was determined according to the experimental method. The found results were consistent with the theoretical values.