2023-07-20 ワシントン州立大学(WSU)
◆このシングルアトム触媒技術は、メタンという最悪の温室効果ガスの排出量を削減する可能性を持ちます。これまでの触媒技術では、低温での効果が不十分であったり、高温では劣化してしまう問題がありましたが、このシングルアトム触媒は低温でも効果的であり、高温でも安定して機能します。
◆研究者たちは今後もこの技術を進化させる予定で、商業化に向けて産業パートナーや研究機関と共同研究を行っています。これにより、世界中の車両やガス産業での排気ガスに含まれるメタンの削減が可能になると期待されています。
＜関連資料＞
- https://news.wsu.edu/press-release/2023/07/20/catalyst-can-control-methane-emissions-in-natural-gas-engines/
- https://www.nature.com/articles/s41929-023-00983-8
効率的なメタン除去のためのセリア上のサブナノメートルサイズのパラジウムの動的かつ可逆的な変換 Dynamic and reversible transformations of subnanometre-sized palladium on ceria for efficient methane removal
Dong Jiang,Gang Wan,Joakim Halldin Stenlid,Carlos E. García-Vargas,Jianghao Zhang,Chengjun Sun,Junrui Li,Frank Abild-Pedersen,Christopher J. Tassone & Yong Wang
Nature Catalysis Published:20 July 2023
DOI:https://doi.org/10.1038/s41929-023-00983-8
Abstract
Reversibly adjusting the active structures of supported metal catalysts in response to dynamic working conditions has long been pursued. Here we report the reaction-environment-modulated transformations of subnanometre-sized Pd on CeO2 for efficient methane removal, leveraging the reaction environments at different stages of automotive exhaust aftertreatment. During the cold start of vehicles, inactive Pd1 single atoms are readily transformed into PdOx subnanometre clusters by CO even at room temperature with excess O2, resulting in boosted low-temperature CH4 oxidation. At elevated temperatures, dispersion of PdOx cluster into Pd1 against metal sintering renders outstanding hydrothermal stability to the catalyst, to be activated during the next vehicle start. Combined experimental and computational studies elucidate the dynamically evolved Pd speciation on CeO2 at an atomic level. Modulating the reversible nature of supported metals helps overcome the long-existing trade-off between low-temperature activity and high-temperature stability, also providing a new paradigm for designing intelligent catalysts that brings single-atom/cluster catalysts closer to real applications.
