文献类型：期刊文献

英文题名：Comparative DFT study on the catalytic decomposition of HAN???HN dimer and HN on defective Ir surfaces

作者：Shi, Zihan[1];Hu, Xu[1];Shen, Yu[1];Yao, Tianliang[2];Huang, Yongmin[1]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Specially Funct Polymer Mat & Related Tech, Minist Educ, Shanghai 200237, Peoples R China;[2]Shanghai Engn Res Ctr Space Engine, Shanghai Inst Space Prop, Shanghai 201112, Peoples R China

年份：2026

卷号：733

外文期刊名：APPLIED SURFACE SCIENCE

收录：;EI(收录号：20261220308292);WOS:【SCI-EXPANDED(收录号:WOS:001719670200001)】；

基金：This work was sponsored by the Fundamental Research Funds for the Central Universities (No. JKD01251701) and Program of Shanghai Ac-ademic/Technology Research Leader (No. 22XD1422000) .

语种：英文

外文关键词：Hydroxylammonium nitrate; Hydrazine nitrate; DFT; Catalytic decomposition

摘要：Since hydroxylamine nitrate (HAN) and hydrazine nitrate (HN) often coexist as mixtures in propellants and their combination has been shown to improve ignition performance while retaining the low toxicity and high density impulse of HAN-based systems, studying their associated dimer (HAN center dot center dot center dot HN dimer) is necessary. This work presents the first comparative DFT investigation of HAN-HN Complex and HN decomposition on Ir surfaces. Pristine and defective Ir models, including single vacancy (D-V1), double vacancy (D-V2), stepped (D-S1) and high-index (D-S(331)) surfaces, are examined. Defective Ir surfaces exhibit stronger adsorption and enhanced charge transfer, forming defect-stabilized adsorption modes with shortened Ir-O distances. Electronic analysis shows that symmetry breaking activates Ir 5dxz and 5dyz orbitals, fostering it-character and it-backdonation that strengthen surface interactions. HAN center dot center dot center dot HN dimer formation alters the intrinsic decomposition pathway of HN, initiating N-O(1) cleavage instead of N-O(2). Vacancy defects hinder dissociation by limiting O adsorption sites, while the D-S1 stepped surface enables barrierless decomposition through bridge-site adsorption. -ICOHP results confirm that stepped defects reinforce it-interactions and reduce antibonding occupation. Overall, a defectinduced it-backdonation mechanism enhances adsorption, catalytic activity, and stability, indicating that stepped Ir surfaces are more favorable than vacancy-type defects for HAN-HN-based propellant decomposition.