麻豆淫院

Researchers have successfully improved a catalyst used in dry reforming reactions that produce energy from greenhouse gases. The newly developed self-generating catalyst offers high durability and significantly reduces metal usage compared to conventional catalysts, greatly enhancing economic efficiency.

The work is in the journal ACS Catalysis. The team included Dr. Heeyeon Kim and Dr. Yoonseok Choi from the High Temperature Electrolysis Laboratory at the Korea Institute of Energy Research, in collaboration with Professor WooChul Jung from the Department of Materials Science and Engineering at Seoul National University.

Dry reforming is a technology that reacts with methane (CH鈧�) and carbon dioxide (CO鈧�)鈥攂oth major greenhouse gases鈥攁t high temperatures to synthesize hydrogen (H鈧�) and carbon monoxide (CO). By reducing greenhouse gases, it helps combat global warming while producing hydrogen, a key energy source, and versatile syngas. For these reasons, it has been an active area of research in both academia and industry.

Dry reforming reactions typically use nickel (Ni) catalysts, which are both cost-effective and high-performing. However, during the reaction, carbon tends to deposit on the catalyst surface, leading to a rapid decline in performance. This coke deposition is a major obstacle to long-term operation and commercialization, driving active research into new catalyst designs and optimization of operating conditions.

As an alternative, self-generating catalyst technology using perovskite-based oxides has been getting a lot of attention. In this approach, the metal resides within the catalyst support and migrates to the surface to form catalytic active sites under reaction conditions. The metal particles that emerge bond strongly with the support, effectively suppressing carbon deposition. As a result, compared to conventional nickel catalysts, self-generating catalysts can maintain performance over long-term operation.

The research team optimized the interatomic bonding strength to develop a self-generating catalyst that operates stably even under the high-temperature conditions of dry reforming reactions. Using this catalyst, the same amount of syngas can be produced with only about 3% of the nickel required by conventional catalysts.

In self-generating catalysts, the easier it is for the internal metal elements to migrate to the surface, the faster the reaction rate. However, the lanthanum manganite (LaMnO鈧�)-based perovskite oxide support used in this study had strong interatomic bonds, making it difficult for the internal metal particles to emerge. To address this, the research team substituted lanthanum ions (La鲁鈦�) in the oxide support with calcium ions (Ca虏鈦�), reducing the interatomic bonding strength and enabling a greater amount of nickel to migrate to the catalyst surface.

However, the team found that adding an excessive amount of calcium could cause the perovskite structure itself to collapse, leading to reduced catalyst stability and activity. Based on this finding, they determined the optimal range of calcium substitution and successfully developed a self-generating catalyst that operates stably while offering high resistance to carbon deposition and strong reforming activity.

When compared with conventional catalysts, the newly developed catalyst required only about 3% of the nickel to produce the same amount of syngas. Moreover, unlike conventional catalysts, whose activities are easily reduced by agglomeration and coking, the new catalyst maintained high conversion efficiency stably for 500 hours of long-term operation at 800 掳C, with no signs of carbon deposition鈥攄emonstrating its outstanding durability.

Dr. Kim, the lead researcher, stated, "The self-generating catalyst technology is a groundbreaking innovation that not only effectively resolves the catalyst deactivation issues mainly by coke deposition of conventional nickel catalysts but also significantly reduces the costs of raw materials and reaction processes."

Dr. Choi, co-corresponding author of the paper, commented, "This work is highly significant as it has secured a core technology applicable not only to dry reforming reactions but also to a wide range of hydrocarbon reforming processes, high-temperature water electrolysis (SOEC), and other next-generation energy conversion systems."