'Carbon Dioxide + Methane = Hydrogen Production' High-Efficiency Catalyst Development

UNIST Professor Kim Geontae's Team Develops Catalyst for Methane Dry Reforming Reaction with Excellent Performance and Stability

[Asia Economy Reporter Kim Bong-su] A new catalyst that produces hydrogen by reacting carbon dioxide and methane has been developed. It is attracting attention as a two-in-one technology that decomposes greenhouse gases to produce eco-friendly fuel.

Ulsan National Institute of Science and Technology (UNIST) announced on the 10th that Professor Kim Geon-tae's team from the Department of Energy and Chemical Engineering developed a catalyst for methane dry reforming reaction with excellent performance and stability. Methane dry reforming reaction is a technology that chemically reacts methane and carbon dioxide, which are greenhouse gases, to produce hydrogen and carbon monoxide, an industrial raw material. Catalysts are used to reduce the energy consumed in the chemical reaction.

The catalyst developed by the research team has ternary alloy nanoparticles protruding on the catalyst surface. The alloy nanoparticles contain three metal elements (cobalt, nickel, iron), which promote methane decomposition (dissociation) reaction better than existing catalysts.

Researcher Joo Sang-wook explained, “The alloy nanoparticles loosen the chemical bonds of methane to promote decomposition,” adding, “This is due to the change in the electronic structure (d-band shift) of the alloy nanoparticles caused by the addition of iron.”

Using 1 gram of the developed catalyst can convert about 1.2x10¹⁹ methane molecules per second at 900 °C. This is about an 84.8% increase compared to single-phase catalysts. It also demonstrated stability by operating well for over approximately 350 hours at 750 °C.

Generally, nickel metal-based catalysts are used for dry methane reforming reactions. Although they perform well, there are issues such as catalyst particles agglomerating at high temperatures and solid carbon accumulating on the catalyst surface with repeated reactions.

The catalyst developed by the research team is a type of ‘smart self-regenerating (exsolution) catalyst.’ It utilizes the exsolution phenomenon where metal elements inside the catalyst particles emerge to the surface after repeated reactions. As the surface regenerates with new metal nanoparticles, the catalyst performance can be maintained for a long time. Especially, when nickel (Ni) or cobalt (Co) metals are exsolved, they form a nano-alloy with excellent performance.

In this study, a thin layer of iron was coated on the catalyst particle surface to facilitate the migration of nickel and cobalt metals to the surface. Additionally, the exsolved nickel and cobalt particles mixed with iron to form a new ternary alloy, further improving performance. This is the first discovery of a ternary alloy.

Jin-kyung Oh, a master's course researcher in the Department of Energy Engineering at UNIST, said, “Using the newly developed method (Topotactic exsolution), not only could we create a ternary catalyst, but we also produced over 200 alloy nano catalyst particles per unit area, enhancing the dry reforming catalyst reactivity.”

Professor Kim Geon-tae said, “To stably produce synthesis gas and hydrogen through methane dry reforming reaction, catalyst activity and stability must be supported,” and added, “This study, which developed a catalyst material satisfying both conditions simultaneously, will contribute to the commercialization of methane dry reforming.”

The research results were published online on the 7th in the international chemistry journal Angewandte Chemie International Edition and will be published soon.

This content was produced with the assistance of AI translation services.