Search

Platinum group metals (PGMs) are regarded as strategic metals due to high melting point, corrosion resistance and catalytic activity. They are widely employed in renewable energy, petrochemical industry, vehicles and pharmaceutical engineering. However, the supply and demand of PGMs are facing challenges stemming from rarity and unequal distribution across the globe. This review aims to delve into the supply-demand of PGMs to elucidate primary applications and pinpoint current or projected shortfalls in the supply chain. The future demand for PGMs indicates a significant increase, particularly within the hydrogen sector. It is anticipated that Pt and Ir consumption in fuel cell vehicles and proton exchange membrane electrolysis will reach 143 tons and 38 tons by 2050, respectively. Production of PGMs is far from meeting demand. Sustainable development strategies, including recycling, substitution and innovative technologies, are proposed to address this contradiction. Recycling serves as a strategy to increase PGMs supply. Nevertheless, recycled PGMs accounted for approximately 26 %. Substitution represents a pathway to decrease the PGMs contents in products. The Pt load in fuel cells declined from 1.0 g kW−1 in the 1990s to 0.3 g kW−1 nowadays. Innovative technologies can mitigate the PGMs demand. Electric vehicles, solid oxide fuel cells and electrolysis cells provide promising alternatives for PGMs intensive industry. Ultimately, key future development directions for PGMs are outlined. The emphasis should lie on enhancing PGMs recovery efficiencies and intensifying research into catalytic mechanisms. Notably, ensuring the secure supply of PGMs will facilitate the advancement of renewable and sustainable energy. [Display omitted] • The supply and demand for PGMs is serious imbalance. • The demand for PGMs is forecasted, especially hydrogen industry. • PGMs sustainable strategies include recycle, substitution, innovative technologies. • Challenges and suggestions for PGMs sustainable development are raised. [ABSTRACT FROM AUTHOR]

Reclamation of spent catalysts for the efficient recovery of palladium (Pd) is gaining growing attention due to its scarcity and high supply risk. Currently Pd extraction from spent catalysts through an efficient, economical, and green method has remained a challenge. In this study, Fe3+ is utilized for leaching through oxidation of Pd in a mild condition. Before leaching, distillation was proposed to remove and recover the organics from spent catalysts. The effects of HCl concentration, Fe3+ concentration, NaCl concentration, leaching time, and temperature on the leaching efficiency of Pd were investigated to determine the optimum leaching conditions. The results show that Pd extraction and dissolution of Al2O3 increase with higher HCl concentration. The effect of NaCl on Pd leaching efficiency is significant at low acid concentration (2.0 mol/L HCl). The leaching efficiency was 99.5% for Pd under the following conditions: 2.0 mol/L HCl, 4.0 mol/L NaCl, and 0.67 mol/L Fe3+ at 80 °C for 90 min. The leaching kinetics fits best to the shrinking-core model of surface chemical reaction. The activation energy for the leaching of Pd was 47.6 kJ/mol. PdCl42− was selectively adsorbed by anion exchange resin. The filtrate containing adequate H+, Cl-, and Fe3+ was reused as leaching agent. Pd leaching efficiency was over 96% after five cycle times. This study provides an efficient process for recovery of Pd from spent catalysts. [ABSTRACT FROM AUTHOR]