Alkali and Alkaline Earth Hydrides-Driven N-2 Activation and Transformation over Mn Nitride Catalyst
发布时间：2020-05-23
点击次数：
影响因子：14.695
DOI码：10.1021/jacs.8b08334
所属单位：Chinese Acad Sci, Dalian Inst Chem Phys
发表刊物：J. Am. Chem. Soc.
摘要：Early 3d transition metals are not focal catalytic candidates for many chemical processes because they have strong affinities to O, N, C, or H, etc., which would hinder the conversion of those species to products. Metallic Mn, as a representative, undergoes nitridation under ammonia synthesis conditions forming bulk phase nitride and unfortunately exhibits negligible catalytic activity. Here we show that alkali or alkaline earth metal hydrides (i.e., LiH, NaH, KH, CaH2, and BaH2, AHs for short) promotes the catalytic activity of Mn nitride by orders of magnitude. The sequence of promotion is BaH2 > LiH > KH > CaH2 > NaH, which is different from the order observed in conventional oxide or hydroxide promoters. AHs, featured by bearing negatively charged hydrogen atoms, have chemical potentials in removing N from Mn nitride and thus lead to significant enhancement of N-2 activation and subsequent conversion to NH3. Detailed investigations on Mn-LiH catalytic system disclosed that the active phase and kinetic behavior depend strongly on reaction conditions. Based on the understanding of the synergy between AHs and Mn nitride, a strategy in the design and development of early transition metals as effective catalysts for ammonia synthesis and other chemical processes is proposed.
合写作者：Xingguo, 邹理, Jie, Zheng, Guotao, Wu, Wenbo, Gao, Peikun, Wang, Xinghua, Chang, Yeqin, Guan
第一作者：Fei, Chang
论文类型：期刊论文
通讯作者：Jianping, Guo
一级学科：0805 材料科学与工程
文献类型：J
是否译文：否
发表时间：2018-11-01