fig2

Figure 2. (A) Temperature dependence of the NH₃ synthesis rates of BaH₂-Co/CNTs and BaO-Co/CNTs. The insert of (A) shows the three steps of NH₃ synthesis catalyzed by BaH₂-Co/CNTs. Reproduced from Ref^[30]. Copyright (2017), with permission from American Chemical Society; (B) Comparison of NH₃ yield of different catalysts, reaction condition: 10 bar syn-gas (N₂:H₂ = 1:3), 573 K, 60,000 mL·g·cat^-1·h^-1 WHSV; (C) Scheme for designing highly active ETM catalysts stimulated by Mn₄N-AHs was proposed. ETMs (active center 1) activate the reactant to form adsorbent A’, and active center 2 pulls A’ away from center 1 to form more stable A”, thereby releasing center 1 and allowing A to continue to be activated. A” can be combined with another reactant B or the active substance B’ to produce the final product. Reproduced from Ref^[31]. Copyright (2018), with permission from American Chemical Society. CNTs: Carbon nanotubes; ETM: early 3d transition metal; AHs: alkaline-metal hydrides.