氨合成反应的BOC-MP法研究  

BOC MP Study for Ammonia Synthesis

作　　者：黑美军[1] 陈鸿博[1] 林贻基[1] 洪琦[1] 林银钟[1] 易军[1] 廖代伟[1] 蔡启瑞[1] 

机构地区：[1]厦门大学物理化学研究所化学系固体表面物理化学国家重点实验室

出　　处：《厦门大学学报（自然科学版）》1997年第6期879-884,共6页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金;福建省自然科学基金;国家教委留学回国人员科研资助

摘　　要：用键级守恒莫尔势函数法（ＢＯＣ－ＭＰ）研究了铁催化剂表面氨合成反应的缔合式和解离式两种机理，计算表明缔合式机理速控步骤的活化能垒Ｎ２，ａｄ＋Ｈａｄ→ＮＨａｄ＋Ｎ（９２ｋＪｍｏｌ－１）低于解离式机理速控步骤Ｎａｄ＋Ｈａｄ→ＮＨａｄ（１６３ｋＪｍｏｌ－１）的活化能垒，但反应Ｎ２，ａｄ→Ｎａｄ＋Ｎａｄ（５０ｋＪｍｏｌ－１）的活化能垒又明显低于缔合式途径速控步骤的活化能垒．由此可推断，在铁催化剂表面存在着两种氨合成竞争反应途径，但缔合式机理在反应能量学上较为有利．Both mechanisms of ammonia synthesis, the associative and the dissociative, on iron catalysts are studied with the Bond order conservation Morse potential (BOC MP) approach. The calculations indicated that the activation barrier of the rate(determining step, N 2,ad +H ad NH ad +N ad (92 kJ mol -1 ) for the associative pathway is lower than that of the N ad +H ad NH ad (163 kJ mol -1 ) for the dissociative pathway. Howerver, the activation barrier for reaction, N 2,ad N ad +N ad (50 kJ mol -1 ) is lower more much than that of rate determining step, N 2,ad +H ad NH ad +N ad for the associative pathway. It is shown that there are two competitive reaction pathways for ammonia synthesis on iron catalysts but the associative pathway is more favorable in catalytic reaction energy.

关 键 词：合成氨 铁催化剂 BOC-MP法 动力学 

分 类 号：TQ113.21[化学工程—无机化工]