Ma Zili, Chen Jianhong, Luo Dongbao, Thersleff Thomas, Dronskowski Richard, Slabon Adam
Chair of Solid-State and Quantum Chemistry, Institute of Inorganic Chemistry, RWTH Aachen University, 52056 Aachen, Germany and Department of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden.
Department of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden.
Nanoscale. 2020 Oct 1;12(37):19276-19283. doi: 10.1039/d0nr04981f.
Metal nitrides have been suggested as prospective catalysts for the electrochemical nitrogen reduction reaction (NRR) in order to obtain ammonia at room temperature under ambient pressure. Herein, we report that templated chromium nitride porous microspheres built up by nanocubes (NCs) are an efficient noble-metal-free electrocatalyst for NRR. The CrN NCs catalyst exhibits both a high stability and NH3 yield of 31.11 μg h-1 mgcat.-1 with a Faradaic efficiency (FE) of 16.6% in 0.1 M HCl electrolyte. Complementary physical characterization techniques demonstrate partial oxidation of the pristine CrN NCs during reaction. Structural characterization by means of scanning transmission electron microscopy (STEM) combining electron energy loss spectrum (EELS) and energy dispersive X-ray spectroscopy (EDX) analysis reveals the NC structure to consist of an O-rich core and N-rich shell after NRR. This gradient distribution of nitrogen within the CrN NCs upon completed NRR is distinct to previously reported metal nitride NRR catalysts, because no significant loss of nitrogen occurs at the catalyst surface.
为了在室温常压下获得氨，金属氮化物已被认为是用于电化学氮还原反应（NRR）的潜在催化剂。在此，我们报道由纳米立方体（NCs）构建的模板化氮化铬多孔微球是一种用于NRR的高效无贵金属电催化剂。在0.1 M HCl电解质中，CrN NCs催化剂表现出高稳定性，NH₃产率为31.11 μg h⁻¹ mgcat.⁻¹，法拉第效率（FE）为16.6%。互补的物理表征技术表明，在反应过程中原位CrN NCs发生了部分氧化。通过扫描透射电子显微镜（STEM）结合电子能量损失谱（EELS）和能量色散X射线光谱（EDX）分析进行的结构表征表明，NRR后NC结构由富O核和富N壳组成。与之前报道的金属氮化物NRR催化剂不同，在完成NRR后，CrN NCs中氮的这种梯度分布在催化剂表面没有明显的氮损失。
