KIER Develops New Catalyst for Syngas Production from Greenhouse Gases

A new catalyst that produces syngas from greenhouse gases, the main culprit of global warming, has been developed in South Korea.

The Korea Institute of Energy Research (KIER) announced on August 13 that a research team led by Dr. Heeyeon Kim and Dr. Yunseok Choi at the High-Temperature Water Electrolysis Laboratory, in collaboration with Professor Woochul Jung's team at the Department of Materials Science and Engineering at Seoul National University, has successfully developed a self-generating catalyst by improving the "dry reforming reaction" catalyst.

(From left) Sojung Kim, Researcher at EGI; Yunseok Choi, Senior Researcher; Heeyeon Kim, Principal Researcher; Seongwoo Nam, PhD at Seoul National University; Woochul Jung, Professor. Provided by Korea Institute of Energy Research

The dry reforming reaction is a technology that produces syngas by reacting methane and carbon dioxide-both major greenhouse gases-at high temperatures. Recently, this technology has gained attention as a key method for distributed hydrogen production linked with hydrocarbons and for integrated power generation systems with solid oxide fuel cells.

Nickel (Ni) catalysts, which are both inexpensive and highly efficient, are mainly used in dry reforming reactions. However, nickel catalysts suffer from a rapid decline in performance due to carbon accumulating on the catalyst surface during the reaction process. This carbon deposition poses a significant obstacle to long-term operation and commercialization, prompting active research into new catalyst designs and optimization of operating conditions.

The self-generating catalyst technology utilizing perovskite-structured oxides is emerging as a promising alternative to nickel catalysts. In this approach, the metal exists within the support material and, under reaction conditions, migrates to the surface to form active reaction sites. The metal particles that emerge bond strongly with the support, effectively suppressing carbon deposition and maintaining performance over extended periods of operation.

Using this approach, the joint research team optimized the atomic bonding strength to develop a self-generating catalyst that operates stably even under the high-temperature conditions required for dry reforming reactions.

Typically, the faster the internal metal elements of a self-generating catalyst migrate to the surface, the faster the reaction proceeds. However, the lanthanum manganite (LaMnO3)-based perovskite oxide support used in this study exhibited strong atomic bonding, making it difficult for internal metal particles to migrate to the surface.

To overcome this challenge, the joint research team substituted lanthanum ions (La3+) with calcium ions (Ca2+) within the oxide support, thereby reducing the atomic bonding strength and enabling a greater amount of nickel to migrate to the catalyst surface. Additionally, by determining the optimal range for calcium substitution, the team succeeded in developing a self-generating catalyst that demonstrates both resistance to carbon deposition and high reforming reaction activity, while maintaining stable operation.

When comparing the newly developed catalyst with conventional catalysts, the amount of nickel required to produce the same level of syngas was reduced to just 3% of that needed for traditional catalysts. Most notably, while conventional catalysts experience gradual performance degradation during continuous operation, the new catalyst maintained high conversion efficiency even after long-term operation (500 hours) at 800 degrees Celsius, with no observed carbon deposition, thereby proving its durability.

Dr. Heeyeon Kim stated, "Self-generating catalyst technology will not only effectively resolve the carbon deposition issues associated with conventional nickel catalysts, but also significantly reduce raw material and process costs."

This research was supported by KIER's basic research program and the Basic Research Program of the Ministry of Science and ICT. The results were recently published in the American Chemical Society's journal, ACS Catalysis.

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