Tanaka Kikinzoku Develops Low-Temp Palladium Alloy Membrane for Hydrogen Purification
New PdCu39 alloy enables hydrogen purification at 300°C, eliminating need for extra heating equipment
• Promises lower energy use, reduced CO₂ emissions, and more compact system design
Tokyo-based Tanaka Kikinzoku Kogyo has announced the development of a palladium-copper hydrogen-permeable membrane capable of purifying hydrogen at low temperatures of around 300°C, a major improvement over existing PdCu40 alloys that typically require 400°C. The new material, dubbed PdCu39, achieves high hydrogen permeability through a fully bcc crystalline phase, a feat previously considered unfeasible due to phase instability issues. Sample distribution begins on September 15, and the breakthrough will be presented at the Japan Institute of Metals 2025 Autumn Conference at Hokkaido University.
Conventional hydrogen-purification systems using palladium-based membranes often rely on methanol–water reforming to produce hydrogen at 300°C—but existing membranes only function efficiently at higher temperatures, requiring costly additional heating equipment. Tanaka’s PdCu39 membrane not only functions at reformer-matched temperatures but also suppresses oxidation, eliminates pinholes, and lowers operational energy demand, making it well-suited for compact hydrogen purification modules. “This technology reduces both CO₂ emissions and equipment deterioration,” the company said.
PdCu39 is the result of proprietary heat treatment techniques developed over decades of precious metals research. By fine-tuning the palladium-to-copper ratio to 61:39 and avoiding the fcc phase that inhibits permeability, Tanaka’s metallurgists have achieved performance previously unattainable with existing PdCu membranes. As demand for low-temperature hydrogen purification grows across hydrogen-from-methanol, fuel cell, and distributed reforming applications, PdCu39 is expected to offer significant cost and system design advantages—particularly where space, temperature, and energy efficiency are critical.
About Tanaka Kikinzoku
Tanaka Kikinzoku was founded in 1885 (Meiji 18) and has since engaged in a wide range of activities in business areas centered on precious metals. Tanaka Kikinzoku handles some of the largest volumes of precious metals in Japan, and for many years has been manufacturing and selling industrial precious metal products, as well as providing precious metal products for investment and jewelry. As a group of precious metals experts, domestic and international group companies collaborate and cooperate in manufacturing, sales, and technological development to provide products and services.
Consolidated sales for fiscal year 2024 (ending December 2024) are expected to reach 846.9 billion yen, with 5,591 employees.
Source: FCW Team