Asymmetric Dual-Atom Ru Anchored in Boron Nitride Nanolayer Triggers Mechanism Transition for Stable Dry Reforming
Asymmetric Dual-Atom Ru Anchored in Boron Nitride Nanolayer Triggers Mechanism Transition for Stable Dry Reforming
研究概述
在氮化硼纳米层锚定配位不对称的Ru双原子，分别促进CH4断键和CO2活化，协同降低生成*CH2O的反应势垒并抑制积碳。650℃下CH4和CO2转化率分别69%和76%；600℃下稳定运行1000小时。
谱图与表征信息
Figure 2. Identification of dual-atom Ru structures. (a−c) Representative AC-HAADF-STEM images of Ru2/SiO2@BN, with the insets showing line-scanning intensity profiles of Ru dual-atoms. (d) Statistical distribution of the Ru···Ru distance in the Ru dual-atoms derived from the STEM images. (e) Fourier-transform XAFS spectra of the Ru K-edge for Ru1/SiO2@BN, Ru2/SiO2@BN, and reference samples. (f) Wavelet-transformed k2-weighted EXAFS spectra of Ru1/SiO2@BN, Ru2/SiO2@BN, and reference samples. (g) Geometric parameters and (h) fitting of the EXAFS spectrum of Ru1/SiO2@BN. (i) Geometric parameters and (j) fitting of the EXAFS spectrum of Ru2/SiO2@BN.
Figure 3. Chemical state analysis of the Ru2/SiO2@BN catalyst. (a−c) XPS profiles of B 1s, N 1s, and Ru 3p of Ru1/SiO2@BN, Ru2/SiO2@BN, and reference samples. Due to an overlap of the Ru 3d with the C 1s signal, the Ru speciation was analyzed based on Ru 3p spectra. (d) Ru K-edge XANES spectra for Ru1/SiO2@BN, Ru2/SiO2@BN, and reference samples. The inset shows the fitted pre-edge region. (e) The average oxidation states of Ru in Ru1/SiO2@BN, Ru2/SiO2@BN, and reference samples. (f,g) Charge-density difference plots of the Ru1/SiO2@BN and Ru2/SiO2@ BN configurations (isosurface level is 0.1 e/Å). Yellow and cyan isosurfaces represent charge accumulation and charge depletion, respectively. Red regions indicate charge accumulation; blue regions indicate charge depletion in 2D maps.