Sekine Yasushi
Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo, Japan, 1698555.
Faraday Discuss. 2023 Jul 19;243(0):179-197. doi: 10.1039/d2fd00146b.
Low-temperature ammonia synthesis by applying an electric field to a solid heterogeneous catalyst was investigated to realize an on-demand, on-site catalytic process for converting distributed renewable energy into ammonia. By applying an electric field to the catalyst, even at low temperatures, the reaction proceeds efficiently by an "associative mechanism" in which proton-conducting species on the support surface promote the formation of NH intermediates through surface protonics. Kinetics, isotope exchange, infrared spectroscopy, X-ray spectroscopy, and AC impedance analysis were performed to clarify the effect of metal and catalyst support structure on the reaction, and an evaluation method for the surface protonics of the support was established to analyze the reaction mechanism, and further analysis using computational chemistry was also conducted. The elementary step determining catalytic activity changed from N dissociation to NH formation, and this difference resulted in high activity for ammonia synthesis at low temperatures even when using base metal catalysts such as Fe and Ni.
通过对固体多相催化剂施加电场来进行低温氨合成的研究，以实现将分布式可再生能源转化为氨的按需、现场催化过程。通过对催化剂施加电场，即使在低温下，反应也能通过“缔合机制”高效进行，其中载体表面的质子传导物种通过表面质子学促进NH中间体的形成。进行了动力学、同位素交换、红外光谱、X射线光谱和交流阻抗分析，以阐明金属和催化剂载体结构对反应的影响，建立了载体表面质子学的评估方法来分析反应机理，并利用计算化学进行了进一步分析。决定催化活性的基本步骤从N解离转变为NH形成，这种差异导致即使使用Fe和Ni等贱金属催化剂，在低温下氨合成也具有高活性。
