Abstract The capture of Hg0 in syngas is challenging since the reducing atmosphere is disadvantageous to oxidize Hg0. Spinel CoxMn3−xO4 sorbents synthesized by a low-temperature sol-gel auto-combustion method were employed for the first time to remove Hg0 under simulated syngas. The Hg0 capture performance of CoxMn3−xO4 sorbents increased with Co mole ratio increases. CoMn2O4 showed the highest Hg0 capture performance among the CoxMn3−xO4 sorbents, attained over 95% Hg0 removal efficiency at 40–160 °C. The characterization results indicated that the mobile-electron environment, higher contents of surface Co and chemisorbed oxygen, larger BET surface area of CoMn2O4 sorbent were responsible for its superior performance. Ten repeated adsorption-regeneration cycles demonstrated that the regenerability of CoMn2O4 sorbent is excellent. Density functional theory (DFT) calculations were performed to determine the active sites of CoMn2O4 and to reveal Hg0 adsorption mechanism. The results suggested that Hg0 was chemisorbed on CoMn2O4 with a high adsorption energy (−1.04 eV). The two-fold coordinated surface Co atom was determined as the major active site for Hg0 adsorption. The strong orbital hybridization between Hg and Co atoms resulted in the strong chemisorption of Hg0 on CoMn2O4 surface.

中文翻译：

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用于从合成气中去除元素汞的可再生 CoxMn3−xO4 尖晶石吸附剂：实验和 DFT 研究

摘要 由于还原气氛不利于氧化 Hg0，因此在合成气中捕获 Hg0 具有挑战性。首次采用低温溶胶-凝胶自燃法合成的尖晶石 CoxMn3−xO4 吸附剂在模拟合成气下去除 Hg0。CoxMn3−xO4 吸附剂的 Hg0 捕获性能随着 Co 摩尔比的增加而增加。CoMn2O4 在 CoxMn3−xO4 吸附剂中表现出最高的 Hg0 捕获性能，在 40-160 °C 下达到 95% 以上的 Hg0 去除效率。表征结果表明，CoMn2O4 吸附剂的移动电子环境、较高的表面 Co​​ 和化学吸附氧含量、较大的 BET 表面积是其优越性能的原因。十次重复的吸附-再生循环表明 CoMn2O4 吸附剂的再生性非常好。进行密度泛函理论 (DFT) 计算以确定 CoMn2O4 的活性位点并揭示 Hg0 吸附机制。结果表明，Hg0 以高吸附能（-1.04 eV）化学吸附在 CoMn2O4 上。双重配位的表面 Co​​ 原子被确定为 Hg0 吸附的主要活性位点。Hg 和 Co 原子之间的强轨道杂化导致 Hg0 在 CoMn2O4 表面上的强化学吸附。