In this study mercury sorbent based on manganese oxides impregnated γ-alumina was synthesized. Mercury retention characteristics were investigated by mercury speciation and thermal desorption experiments. No gaseous mercuric oxide was observed in mercury speciation experiments with a mercury mass balance ratio of 89.11%. Maximum mercury desorption peak at 480 °C indicated that mercury was adsorbed in the form of mercuric oxide. Three cycles of mercury retention were tested with different thermal treatment in-between to evaluate the cyclic performance. Changes in surface phase and manganese chemistry before and after thermal treatment were characterized by XRD and XPS. Deterioration in mercury retention capacity was observed after thermal desorption at 500 °C, which was interpreted with reduced initial adsorption rate calculated by Pseudo-second order kinetic model. XPS studies suggested that atomic ratios of Mn⁴⁺/(Mn⁴⁺+Mn³⁺) decreased from 73.2% to 32.3% and 33.9% after thermal desorption in N₂ and air, respectively. The reduction of MnO₂ to Mn₂O₃ was irreversible thus the mercury retention capacity could not be restored by thermal desorption at high temperatures. Spent sorbents that were reactivated at 200 °C in air without thermal desorption at 500 °C possessed considerable cycling performance for mercury retention due to the preserved Mn⁴⁺.

在这项研究中，合成了基于锰氧化物浸渍的γ-氧化铝的汞吸附剂。通过汞形态和热脱附实验研究了汞的保留特性。在汞形态实验中未观察到气态氧化汞，汞质量平衡比为89.11％。在480°C时最大的汞解吸峰表明汞以氧化汞的形式被吸附。测试了三个汞保持周期，并在其间进行了不同的热处理，以评估其循环性能。用XRD和XPS表征了热处理前后的表面相和锰化学变化。在500°C的温度下进行热解吸后，发现汞保留能力下降，用伪二级动力学模型计算得出的降低的初始吸附速率来解释。XPS研究表明锰的原子比⁴⁺ /（MN ⁴⁺ +锰³⁺）从73.2％的N降低至32.3％和33.9％热脱附后₂和空气分别。MnO ₂还原为Mn ₂ O ₃是不可逆的，因此汞保留能力无法通过高温下的热脱附来恢复。废吸附剂在空气中在200°C下重新活化而在500°C下不发生热脱附，由于保留了Mn ^4+，因此具有相当大的汞保持循环性能。