汽車觸媒轉化器中含有鉑族金屬，鉑、鈀及銠，和稀土元素鈰，比起採集天然礦石，從廢棄汽車觸媒轉化器中回收這些金屬更為環保且具有經濟價值。本研究的目的主要為利用次臨界水萃取技術回收廢棄汽車觸媒轉化器中的鉑、鈀、銠及鈰，並探討鹽酸濃度、固液比、萃取時間、萃取溫度及以抗壞血酸作為還原劑對萃取效率的影響。此外為量測樣品中的總金屬含量，比較了不同的方法，包括傳統王水消化、修正王水消化、及微波消化。
實驗結果顯示，相比傳統消化法，在微波系統中進行王水消化，樣品幾乎完全溶解。在次臨界水萃取實驗中，萃取效率隨著鹽酸濃度、萃取時間及萃取溫度的提升和固液比的降低而增加，其中萃取溫度是最具影響力的因素。使用濃度為2.0 M的鹽酸，固液比為10 g/L，在萃取溫度為150℃、萃取時間為30分鐘及初始壓力為10 kg/cm2時，鉑、鈀、銠及鈰的萃取效率分別為70.47%、87.74%、60.30%及102.78%，在高溫下氧化鈰幾乎完全溶解，過程中總共消耗了7.20×10^6 kJ/kg的能量。與傳統萃取法相比，次臨界水萃取法可以在較低的能量需求下獲得更高的萃取效率。

The recovery of platinum (Pt), palladium (Pd), rhodium (Rh), and cerium (Ce) from spent automotive catalytic converters by using subcritical water extraction (SWE) was studied. The effects of HCl concentration, solid to liquid ratio (S/L), leaching time, and leaching temperature were investigated. The leaching efficiency increased with HCl concentration, leaching time, and leaching temperature, while decreased as S/L increased. The leaching temperature was the most influential factor. When using 2.0 M of HCl, at initial pressure of 10 kg/cm2, 10 g/L, at 150℃, reaction time of 30 min, the leaching efficiency of Pt, Pd, Rh, and Ce were 70.47%, 87.74%, 60.30%, and 102.75%, respectively. Total of 7.20×10^6 kJ/kg of energy was consumed in the SWE process. Experimental results showed that SWE could achieve higher leaching efficiency at lower energy requirements compared with conventional leaching methods.

Aarzoo, Nidhi, & Samim M. (2022). Palladium nanoparticles as emerging pollutants from motor vehicles: An in-depth review on distribution, uptake and toxicological effects in occupational and living environment. Science of The Total Environment, 823, 153787.
Argyle, M. D., & Bartholomew, C. H. (2015). Heterogeneous Catalyst Deactivation and Regeneration: A Review. Catalysts, 5(1), 145-269.
Atia T. A., Wouters W., Monforte G., & Spooren J. (2021). Microwave chloride leaching of valuable elements from spent automotive catalysts: Understanding the role of hydrogen peroxide. Resources, Conservation and Recycling., 166, 105349.
Atia, T. A., & Spooren, J. (2021). Fast microwave leaching of platinum, rhodium and cerium from spent non-milled autocatalyst monolith. Chemical Engineering and Processing - Process Intensification, 164, 108378.
Bahaloo-Horeh, N. & Mousavi, S. M. (2022). Efficient extraction of critical elements from end-of-life automotive catalytic converters via alkaline pretreatment followed by leaching with a complexing agent. Journal of Cleaner Production, 344, 131064.
Bahaloo-Horeh, N. & Mousavi, S.M. (2020). Comprehensive characterization and environmental risk assessment of end-of-life automotive catalytic converters to arrange a sustainable roadmap for future recycling practices. Journal of Hazardous Materials. 400, 123186.
Barakat, M. A., & Mahmoud, M. H. H. (2004). Recovery of platinum from spent catalyst. Hydrometallurgy, 72, 179-184.
Barakat, M.A., Mahmoud, M.H.H., & Mahrous, Y.S. (2006). Recovery and separation of palladium from spent catalyst. Applied Catalysis A: General, 301, 182 - 186.
Beaudoux, X., Virot, M., Chave, T., Durand, G., Leturcq, G., & Nikitenko, S.I. (2016). Vitamin C boosts ceria-based catalyst recycling. Green Chemistry, 18(12), 3656-3668.
Birloaga, I., & Vegliò, F. (2022). An innovative hybrid hydrometallurgical approach for precious metals recovery from secondary resources. Journal of Environmental Management, 307, 114567.
Borra, C. R., Vlugt, T. J., Yang, Y., Spooren, J., Nielsen, P., Amirthalingam, M., & Offerman, S. E. (2021). Recovery of rare earths from glass polishing waste for the production of aluminium-rare earth alloys. Resources, Conservation and Recycling, 174, 105766.
Corkhill, C.L., Bailey, D.J., Tocino, F.Y., Stennett, M.C. Miller, J.A. Provis, J.L., Travis, K.P., & Hyatt, N.C. (2016). Role of Microstructure and Surface Defects on the Dissolution Kinetics of CeO2, a UO2 Fuel Analogue. ACS Applied Materials and Interfaces, 8(16), 10562-10571.
de Farias, A.B.V., da Costa, T.B., da Silva, M.G.C., & Vieira, M.G.A. (2021). Cerium recovery from aqueous solutions by bio/adsorption: A review in a circular economy context. Journal of Cleaner Production, 326, 129395.
de Oliveira Demarco J., Stefanello Cadore J., Veit H. M., Bremm Madalosso H., Hiromitsu Tanabe E., & Assumpção Bertuol D. (2020). Leaching of platinum group metals from spent automotive catalysts using organic acids. Minerals Engineering, 159, 106634.
Ding, Y., Zhang, S., Liu, B., Zheng H., Chang, C. C., & Ekberg, C. (2019). Recovery of precious metals from electronic waste and spent catalysts: A review. Resources, Conservation and Recycling, 141, 284-298.
Eskina, V.V., Dalnova, O.A., Filatova, D.G., Baranovskaya, V.B., Karpov, Y.A. (2020). Direct precise determination of Pd, Pt and Rh in spent automobile catalysts solution by high-resolution continuum source graphite furnace atomic absorption spectrometry. Spectrochimica Acta - Part B Atomic Spectroscopy, 165,105784.
Essien, S.O., Young, B., & Baroutian, S. (2020). Recent advances in subcritical water and supercritical carbon dioxide extraction of bioactive compounds from plant materials. Trends in Food Science and Technology, 97, 156-169.
Fajar, A.T.N., Hanada, T., & Goto, M. (2021). Recovery of platinum group metals from a spent automotive catalyst using polymer inclusion membranes containing an ionic liquid carrier. Journal of Membrane Science, 629, 119296.
Golmohammadzadeh, R., Faraji, F., & Rashchi, F. (2018). Recovery of lithium and cobalt from spent lithium ion batteries (LIBs) using organic acids as leaching reagents: A review. Resources, Conservation and Recycling, 136, 418-435.
Harjanto, S., Cao, Y., Shibayama, A., Naitoh, I., Kasahara, K., Okumura, Y., Liu, K., & Fujita, T. (2006). Leaching of Pt, Pd and Rh from Automotive Catalyst Residue in Various Chloride Based Solutions. Materials Transactions, 47(1), 129-135.
Hosseinzadeh, F., Rastegar, S.O., & Ashengroph, M., Gu, T. (2021). Ultrasound assisted Fenton like reagent to leach precious metals from spent automotive catalysts: process optimization and kinetic modeling. International Journal of Environmental Science and Technology, 18(11), 3449-3458.
Hughes, A. E., Haque, N., Northey, S. A., & Giddey, S. (2021). Platinum Group Metals: A Review of Resources, Production and Usage with a Focus on Catalysts. Resources, 10(9), 93.
Johnson Matthey, (2021). https://platinum.matthey.com/
Karim, S. & Ting, Y. P. (2020). Ultrasound-assisted nitric acid pretreatment for enhanced biorecovery of platinum group metals from spent automotive catalyst. Journal of Cleaner Production, 255, 120199.
Kašpar, J., Fornasiero, P., & Hickey, N. (2003). Automotive catalytic converters: Current status and some perspectives. Catalysis Today, 77(4), 419-449.
Kim, D.S. & Lim, S.B. (2019). Subcritical water extraction of rutin from the aerial parts of common buckwheat. Journal of Supercritical Fluids, 152,104561.
Kruse, A., & Dinjus, E. (2007). Hot compressed water as reaction medium and reactant: Properties and synthesis reactions. Journal of Supercritical Fluids, 39(3), 362-380.
Lee, S.H., Jung, C.H., Shon, J.S., & Chung, H. (2000). Separation of Palladium from a Simulated Radioactive Liquid Waste by Precipitation Using Ascorbic Acid. Separation Science and Technology, 35(3), 411-420.
Lemont, F. (2008). Promising optimization of the CeO2/CeCl3 cycle by reductive dissolution of cerium (IV) oxide. International Journal of Hydrogen Energy, 33(24), 7355-7360.
Li, L., Lu, J., Ren, Y., Zhang, X. X., Chen, R. J., Wu, F., & Amine, K. (2012). Ascorbic-acid-assisted recovery of cobalt and lithium from spent Li-ion batteries. Journal of Power Sources, 218, 21-27.
Lima, A.T. & Ottosen, L. (2021). Recovering rare earth elements from contaminated soils: Critical overview of current remediation technologies. Chemosphere, 265, 129163.
Marinho, R.S., Afonso, J.C., & da Cunha, J.W.S.D. (2010). Recovery of platinum from spent catalysts by liquid–liquid extraction in chloride medium. Journal of Hazardous Materials, 179(1-3), 488-494.
Niemelä, M., Pitkäaho, S., Ojala, S., Keiski, R.L., Perämäki, P. (2012). Microwave-assisted aqua regia digestion for determining platinum, palladium, rhodium and lead in catalyst materials. Microchemical Journal, 101, 75-79.
Nogueira, C.A., Paiva, A.P., Oliveira, P.C., Costa, M.C., & da Costa, A.M.R. (2014). Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters. Journal of Hazardous Materials, 278, 82-90.
Okonkwo, E.G., Wheatley, G., He, Y. (2021). The role of organic compounds in the recovery of valuable metals from primary and secondary sources: a mini-review. Resources, Conservation and Recycling, 174,10581.
Omodara, L., Pitkäaho, S., Turpeinen, E.-M., Saavalainen, P., Oravisjärvi, K., & Keiski, R.L. (2019). Recycling and substitution of light rare earth elements, cerium, lanthanum, neodymium, and praseodymium from end-of-life applications - A review. Journal of Cleaner Production, 236, 117573.
PGM market report. (2021).
Saguru, C., Ndlovu, S., & Moropeng, D. (2018). A review of recent studies into hydrometallurgical methods for recovering PGMs from used catalytic converters. Hydrometallurgy, 182, 44-56.
Saidani, M., Kendall, A., Yannou, B., Leroy, Y., & Cluzel, F. (2019). Closing the loop on platinum from catalytic converters: Contributions from material flow analysis and circularity indicators. Journal of Industrial Ecology, 23(5), 1143-1158.
Sasaki, H. & Maeda, M. (2014). Zn-vapor pretreatment for acid leaching of platinum group metals from automotive catalytic converters. Hydrometallurgy, 147-148, 59-67.
Senila, M., Cadar, O., Senila, L., Böringer, S., Seaudeau-Pirouley, K., Ruiu, A., & Lacroix-Desmazes, P. (2020). Performance Parameters of Inductively Coupled Plasma Optical Emission Spectrometry and Graphite Furnace Atomic Absorption Spectrometry Techniques for Pd and Pt Determination in Automotive Catalysts. Materials, 13(22), 5136, 1-13.
Suchá, V., Mihaljevič, M., Ettler, V., & Strnad, L. (2016) The pH-dependent release of platinum group elements (PGEs) from gasoline and diesel fuel catalysts: Implication for weathering in soils. Journal of Environmental Management, 171, 52-59.
Sun, S., Jin, C., He, W., Li, G., Zhu, H., & Huang, J. (2022). A review on management of waste three-way catalysts and strategies for recovery of platinum group metals from them. Journal of Environmental Management, 305,114383.
Sverdrup, H.U., & Ragnarsdottir, K.V. (2016). A system dynamics model for platinum group metal supply, market price, depletion of extractable amounts, ore grade, recycling and stocks-in-use. Resources, Conservation and Recycling 114, 130-152.
Tao, Y., Shen, L., Feng, C., Yang, R., Qu, J., Ju, H., & Zhang, Y. (2022). Distribution of rare earth elements (REEs) and their roles in plant growth: A review. Environmental Pollution, 298,118540.
Teo, C.C., Tan, S.N., Yong, J.W.H., Hew, C.S., & Ong, E.S. (2010). Pressurized hot water extraction (PHWE). Journal of Chromatography A, 1217(16), 2484-2494.
Trinh, H. B., Lee, J. C., Srivastava, R. R., Kim, S., & Ilyas, S. (2017). Eco-threat Minimization in HCl Leaching of PGMs from Spent Automobile Catalysts by Formic Acid Prereduction. ACS Sustainable Chemistry and Engineering, 5(8), 7302-7309.
Trinh, H.B., Lee, J.-C., Kim, S., & Kim, J. (2020). Recovery of Cerium from Spent Autocatalyst by Sulfatizing–Leaching–Precipitation Process. ACS Sustainable Chemistry and Engineering, 8(41), 15630-15639.
Trinh, H.B., Lee, J.-C., Suh, Y.-J., & Lee, J. (2020). A review on the recycling processes of spent auto-catalysts: Towards the development of sustainable metallurgy. Waste Management, 114, 148-165.
United States Geological Survey. (2022). Mineral commodity summaries 2022.
Vanýsek, P. (2014). CRC handbook of chemistry and physics: a ready-reference book of chemical and physical data. 95th edition.
Wei, X., Liu, C., Cao, H., Ning P.b, Jin W.c, Yang Z.a, Wang, H., & Sun, Z. (2019). Understanding the features of PGMs in spent ternary automobile catalysts for development of cleaner recovery technology. Journal of Cleaner Production, 239,118031.
Yakoumis, I., Panou, M., Moschovi, A. M., & Panias, D. (2021). Recovery of platinum group metals from spent automotive catalysts: A review. Cleaner Engineering and Technology, 3, 100112.
Zhang, J., Wen, C., Zhang, H., Duan, Y., & Ma, H. (2020). Recent advances in the extraction of bioactive compounds with subcritical water: A review. Trends in Food Science and Technology, 95,183-195.
Zhao, Z., Qiu, Z., Yang, J., Ma, B., Li, Z., Lu, S., Xu, Y., Cao, L., & Zhang, W. (2020). Recovery of Rare Earth Element Cerium from Spent Automotive Exhaust Catalysts Using a Novel Method. Waste and Biomass Valorization, 11(9), 4967-4976.