The responsible sourcing of platinum-group metals (PGMs) and other critical catalysts is a growing concern in hydrogen production technologies, particularly for electrolysis and steam methane reforming (SMR). These metals, including platinum, iridium, ruthenium, and palladium, are essential for efficient electrochemical reactions but face supply chain challenges due to scarcity, geopolitical risks, and environmental impacts from mining. Addressing these challenges requires a multi-faceted approach, including recycling, material efficiency improvements, alternative catalyst development, and ethical supply chain initiatives.

Platinum-group metals are primarily used in proton exchange membrane (PEM) electrolyzers and fuel cells due to their high catalytic activity and durability. Iridium, for instance, is critical for the oxygen evolution reaction in PEM electrolysis, while platinum facilitates the hydrogen evolution reaction. However, the limited availability of these metals raises concerns about long-term sustainability. Over 70% of global PGM supply comes from just two countries, South Africa and Russia, creating vulnerabilities in the supply chain. This concentration underscores the need for diversification and responsible sourcing practices.

Recycling PGMs from end-of-life catalysts and electronic waste presents a viable solution to reduce primary mining demand. Current recycling rates for platinum and palladium are estimated at around 50%, but technological advancements could improve recovery efficiency. Hydrometallurgical and pyrometallurgical processes are commonly used, though challenges remain in minimizing energy consumption and hazardous byproducts. Closed-loop recycling systems, where manufacturers recover PGMs from spent electrolyzers and fuel cells, are gaining traction. Industry collaborations are also exploring urban mining, where discarded electronics and automotive catalysts are processed to extract valuable metals.

Material efficiency is another critical strategy to reduce PGM dependency. Research indicates that nanostructuring and alloying can enhance catalytic activity, allowing for lower metal loadings without sacrificing performance. For example, platinum-cobalt alloys have demonstrated higher activity than pure platinum in fuel cells, reducing the required amount of the precious metal. Similarly, core-shell catalysts, where a thin layer of PGM coats a cheaper substrate, can achieve comparable performance while using significantly less iridium or platinum. Advances in deposition techniques, such as atomic layer deposition, enable precise control over catalyst layers, further optimizing material use.

Alternative catalyst development is a promising avenue to mitigate reliance on PGMs. Non-precious metal catalysts (NPMCs), such as iron-nitrogen-carbon (Fe-N-C) compounds, have shown potential in alkaline and acidic environments. While their durability remains inferior to PGMs, ongoing research aims to bridge this gap. Transition metal oxides, sulfides, and phosphides are also being investigated for their catalytic properties in water splitting. For SMR, nickel-based catalysts dominate, but efforts are underway to enhance their resistance to coking and sulfur poisoning, reducing the need for additional PGMs as promoters.

The ethical dimension of PGM sourcing cannot be overlooked. Mining activities often involve environmental degradation, water pollution, and labor rights violations. Initiatives like the Initiative for Responsible Mining Assurance (IRMA) and the London Platinum and Palladium Market (LPPM) certification schemes aim to promote sustainable mining practices. Companies are increasingly adopting traceability frameworks to ensure conflict-free and ethically sourced materials. Blockchain technology is being piloted to provide transparent supply chains, from mine to manufacturer.

Industry-led programs are accelerating progress toward sustainable catalyst sourcing. The Hydrogen Council and the International Platinum Group Metals Association (IPA) have established working groups to address supply chain risks. Collaborative projects, such as the European Union’s Critical Raw Materials Alliance, focus on securing PGMs through recycling and substitution. Private-sector investments in alternative catalysts, such as hydrogen-producing enzymes inspired by biological systems, are also gaining momentum.

In summary, reducing dependence on scarce PGMs for hydrogen production requires a combination of recycling innovations, material efficiency improvements, alternative catalyst development, and robust ethical sourcing frameworks. While challenges remain, industry and research initiatives are paving the way for a more sustainable hydrogen economy. By prioritizing responsible practices, stakeholders can ensure that the transition to clean hydrogen does not come at the expense of environmental or social integrity. The integration of these strategies will be crucial in scaling hydrogen technologies while minimizing resource constraints.