氨合成钌基催化剂的研究进展

近年来,钌基氨合成催化剂因其高活性、高稳定性和反应条件温和成为研究热点。综述国内外氨合成钌基催化剂的研究进展,重点介绍钌基催化剂载体、助剂和前驱体对氨合成反应性能的影响。石墨化程度高、导电性能良好的碳载体或氧化物与碳的复合载体是氨合成反应的良好载体;碱金属和碱土金属类助剂通过改变活性金属表面静电场,起到电子助剂的作用,并且碱土金属对反应的促进作用优于碱金属,稀土金属Sm能够抑制碳载体的甲烷化反应;与Ru Cl3相比,Ru3(CO)12是氨合成反应的理想前驱体。简介以电子化合物为载体的钌基氨合成体系,负载钌的高比表面积电子化合物C12A7:e-是强大的电子供体,能够提高氮气在钌上的解离程度,并能可逆地储存氢,有效抑制氢吸附对钌表面的毒害,从而大大提高氨合成反应活性。进一步开发温和条件下非贵金属高效氨合成催化剂将具有重要的理论和现实意义。

Development in ruthenium based catalysts for ammonia synthesis

Recently,ruthenium based catalysts for ammonia synthesis have been attracting interest increasingly due to their higher activity,higher stability and mild reaction conditions.The advance in development of Ru based catalysts for ammonia synthesis at home and abroad,especially the influence of the catalyst supports,promoters and precursors on the performance of ammonia synthetic catalysts were introduced in this paper.The carbon supports,carbon covered oxide and their complex with high graphitic degree and good electrical conductivity were good choice for ammonia synthesis supports.Alkali metals and alkaline-earth metals were good promoters for ammonia synthesis,and the promoting effects of alkaline-earth metals were better than those of alkali metals.Rear earth metals Sm could inhibit carbon methanation.Compared with RuCl₃,Ru₃(CO)₁₂ was the ideal precursor for ammonia synthesis.A electride C₁₂A₇:e^- with high surface area,which worked as an excellent electron donor and reversible hydrogen-storage material,was used as support for Ru based catalyst for ammonia synthesis,and the catalytic activity for ammonia synthesis was greatly enhanced.The development of non-noble metal ammonia synthesis catalysts under mild conditions in the future is also proposed.