A highly selective depressant is of critical importance for efficient Cu-As separation. Herein, the depression mechanism of peracetic acid (PAA) with respect to arsenopyrite is systematically analysed at the microscopic level using density functional theory calculations, molecular dynamics simulations, X-ray photoelectron spectroscopy and coordination chemistry. The adsorption energy of PAA on FeAsS (0 0 1) surfaces is − 550.5 kJ/mol. Both, the single-bonded O (O1) and double-bonded O (O2) atoms of PAA are simultaneously adsorbed onto the Fe atoms of the FeAsS (0 0 1) surfaces, but the covalent bond formed by the O1 and Fe atoms is more stable. Oxidised arsenopyrite surfaces contain an abundance of Fe(III)-O species, while the state of the Cu and Fe atoms on the chalcopyrite surface does not change significantly. The σ-coordination effect of the PAA molecules is more likely to provide lone-pair electrons to the empty e_g orbital of the Fe²⁺ ions on the surface of arsenopyrite than to those on chalcopyrite surfaces. The three pairs of π-electrons in the t_2g orbital of the Fe²⁺ ions on arsenopyrite surfaces are more likely to interact with the empty π-orbital of the PAA molecule in a π-backbonding interaction.

高选择性抑制剂对于有效分离 Cu-As 至关重要。在此，使用密度泛函理论计算、分子动力学模拟、X射线光电子能谱和配位化学在微观水平上系统地分析了过乙酸（PAA）对毒砂的抑制机制。PAA 在 FeAsS (0  0  1) 表面的吸附能为 - 550.5 kJ/mol。PAA 的单键 O (O1) 和双键 O (O2) 原子同时吸附到 FeAsS 的 Fe 原子上 (0  0 1) 表面，但由 O1 和 Fe 原子形成的共价键更稳定。氧化的毒砂表面含有丰富的 Fe(III)-O 物种，而黄铜矿表面的 Cu 和 Fe 原子的状态没有显着变化。PAA分子的σ配位效应更可能为毒砂表面Fe ^{2+离子的空e} _g轨道提供孤对电子，而不是为黄铜矿表面提供孤对电子。毒砂表面Fe ^2+离子的t _2g轨道中的三对π-电子更可能与PAA分子的空π-轨道以π-反键相互作用相互作用。