Reduction of N-2 to NH3 by TiO2-supported Ni cluster catalysts: a DFT study
Reduction of N-2 to NH3 by TiO2-supported Ni cluster catalysts: a DFT study
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TiO2 负载的 Ni 簇催化剂将 N-2 还原为 NH3：DFT 研究
DOI：
10.1039/d1cp00859e
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发表时间：
2021
影响因子：
3.3
通讯作者：
Chen Zhongwei
中科院分区：
文献类型：
--
作者：
Yang Huiru;Luo Dan;Gao Rui;Wang D;an;Li Haibo;Zhao Zhao;Feng Ming;Chen Zhongwei
电化学合成氨技术被认为是一种令人鼓舞的能量转换技术，可以有效地满足氮循环平衡的挑战。在此，我们发现TiO 2（101）负载的Ni 4和Ni 13簇可以作为有效的催化剂，电催化N2还原的基础上的理论计算。电子性质计算表明，在TiO 2表面形成了缺电子的Ni团簇，为N2的吸附和活化提供了多个活性中心.理论计算确定了N2* 在催化剂上的最强活化构型，并证实了氮还原反应（NRR）中的电位限制步骤。在Ni_4-TiO_2（101）上，N2 ~* → NNH ~* 是电位限制步骤，其自由能增量（ΔG）为0.24 eV（对应的过电位为0.33 V），而在Ni_13-TiO_2（101）上，电位限制步骤发生在NH ~* → NH 2 ~*，ΔG为0.49 eV（对应的过电位为0.58 V）。此外，Nin-TiO 2（101）催化剂，特别是Ni 13-TiO 2（101），即使在相应的NRR过电位下也涉及高选择性的NRR。这一工作将为金属氧化物负载的过渡金属簇合物的材料设计提供启发，以实现高效的NRR和NH3合成。
Electrochemical techniques for ammonia synthesis are considered as an encouraging energy conversion technology to efficiently meet the challenge of nitrogen cycle balance. Herein, we find that TiO2(101)-supported Ni4 and Ni13 clusters can serve as efficient catalysts for electrocatalytic N2 reduction based on theoretical calculations. Electronic property calculations reveal the formation of electron-deficient Ni clusters on the TiO2 surface, which provides multiple active sites for N2 adsorption and activation. Theoretical calculation identifies the strongest activated configuration of N2* on the catalysts and confirms the potential-limiting step in the nitrogen reduction reaction (NRR). On Ni4–TiO2(101), N2* → NNH* is the potential-limiting step with a very small free energy increase (ΔG) of 0.24 eV (the corresponding overpotential is 0.33 V), while on Ni13–TiO2(101) the potential-limiting step occurs at NH* → NH2* with ΔG of 0.49 eV (the corresponding overpotential is 0.58 V). Moreover, the Nin–TiO2(101) catalyst, especially Ni13–TiO2(101), involves in a highly selective NRR even at the corresponding NRR overpotential. This work will enlighten material design to construct metal oxide supported transition metal clusters for the highly efficient NRR and NH3 synthesis.