Kinetic Monte Carloによる単原子合金ナノ粒子に対する選択的アセチレン水素化
Mikkel Jørgensen1, Henrik Grönbeck1
1Department of Physics and Competence Centre for Catalysis , Chalmers University of Technology , 412 96 Göteborg , Sweden.
Journal of the American Chemical Society
|May 8, 2019
まとめ
単原子合金,特に銅に埋め込まれたパラジウムは,アセチレン水素化のための触媒の選択性を大幅に高めます. ナノ粒子の設計は,最適なエチレン生産のために,エッジサイトよりも (111) 側面を優先すべきである.
科学分野:
- 材料科学
- カタリシス
- 表面化学
背景:
- 単原子合金では,宿主金属内の金属部位を分離することで,触媒の選択性が向上します.
- ナノ粒子の触媒は 表面積が大きいため 工業用途に不可欠です
研究 の 目的:
- パラジウム・銅 (Pd/Cu) ナノ粒子を用いてアセチレンをエチレンに選択的に水素化することを調査する.
- 拡張されたPd""""とPd""""の表面でPd/Cuナノ粒子の触媒性能を比較する.
主な方法:
- 密度関数理論 (DFT) の計算を用いた.
- 反応メカニズムをモデル化するために,運動モンテカルロ (kMC) シミュレーションが使用された.
主要な成果:
- 銅 (Cu) システムにパラジウム (Pd) を埋め込むことは,選択性を大幅に改善します.
- ナノ粒子の反応メカニズムは 拡張された表面の反応メカニズムと 根本的に異なる.
- ナノ粒子のエッジとコーナーサイトは選択性を低下させることが判明しました.
結論:
- Pd/Cu単原子合金は,アセチレン水素化において優れた選択性を示す.
- 選択的なアセチレン水素化のための触媒の設計は,Pd/Cuナノ粒子のエッジサイトに相対して (111) サイトを最大化する必要があります.
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