Abstract A bench-scale fixed bed reactor was used to study the influences of water vapor and fly ash on Hg0 removal efficiency over CeO2-modified semi-coke adsorbent (Ce/SC). Adsorption results showed that the mercury removal efficiency of Ce/SC decreased by 30% in the presence of 10% water vapor, and the introduction of 0.5 g fly ash had no significant effect on the Hg0 removal efficiency of Ce/SC. In the condition of water vapor and fly ash coexisted, the Hg0 removal efficiency of Ce/SC decreased by only 15%, indicated that the fly ash slowed down the inhibitory effects of water vapor on Hg0 removal efficiency over Ce/SC, which is mainly due to the interaction between water vapor and Fe2O3 in the fly ash to form Fe-OH groups, furthermore, γ-Fe2O3 exhibited higher Hg0 removal performance than α-Fe2O3. Hydrogen temperature-programmed reduction (H2-TPR) revealed that the oxidation activity and capacity of α-Fe2O3 and γ-Fe2O3 increased significantly after water vapor treatment. X-ray photoelectron spectroscopy (XPS) results showed that the Fe-OH content of α-Fe2O3 and γ-Fe2O3 increased from 37.97% and 15.99% to 44.56% and 43.39%, while the lattice oxygen content decreased from 26.53% and 82.46% to 19.08% and 46.49%, respectively. Density functional theory (DFT) calculations revealed that H2O molecules can be dissociated on both α-Fe2O3 (1 0 4) and γ-Fe2O3 (2 2 0) surfaces to form H atoms and OH fragments, the H atoms bound with O atoms in Fe-O groups of both α-Fe2O3 (1 0 4) and γ-Fe2O3 (2 2 0) surfaces, and the OH fragments associated with the adjacent iron atoms of α-Fe2O3 (1 0 4) surface or Fe-O groups of γ-Fe2O3 (2 2 0) surface to form Fe-OH. The formation of Fe-OH groups increased the oxidation activity and Hg0 removal efficiency of Fe2O3.

中文翻译：

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水蒸气和粉煤灰对氧化铈改性半焦脱除元素汞的影响

摘要 采用台式固定床反应器研究了水蒸气和飞灰对CeO2 改性半焦吸附剂(Ce/SC) 去除Hg0 效率的影响。吸附结果表明，在10%的水蒸气存在下，Ce/SC的除汞效率降低了30%，0.5 g飞灰的引入对Ce/SC的Hg0去除效率没有显着影响。在水蒸气和粉煤灰共存的条件下，Ce/SC 的 Hg0 去除效率仅下降 15%，说明粉煤灰减缓了水蒸气对 Ce/SC 的 Hg0 去除效率的抑制作用，主要是由于水蒸气与飞灰中的 Fe2O3 相互作用形成 Fe-OH 基团，γ-Fe2O3 表现出比 α-Fe2O3 更高的 Hg0 去除性能。氢气程序升温还原 (H2-TPR) 表明，α-Fe2O3 和 γ-Fe2O3 的氧化活性和容量在水蒸气处理后显着增加。X射线光电子能谱（XPS）结果表明，α-Fe2O3和γ-Fe2O3的Fe-OH含量从37.97%和15.99%增加到44.56%和43.39%，而晶格氧含量从26.53%和82.46%下降分别为 19.08% 和 46.49%。密度泛函理论 (DFT) 计算表明，H2O 分子可以在 α-Fe2O3 (1 0 4) 和 γ-Fe2O3 (2 2 0) 表面解离形成 H 原子和 OH 碎片，H 原子与 O 原子结合在α-Fe2O3 (1 0 4) 和 γ-Fe2O3 (2 2 0) 表面的 Fe-O 基团，以及与 α-Fe2O3 (1 0 4) 表面或 Fe-O 基团的相邻铁原子相关的 OH 碎片γ-Fe2O3 (2 2 0) 表面形成 Fe-OH。