Hongpan Liu

Herein, FeMnO_x composite catalysts were synthesized using the agar method, aiming to enhance the catalytic performance for toluene oxidation. Compared to traditional preparation methods, the agar‐gel technique leveraged the unique templating effect of biopolymer gels, which promoted the uniform dispersion and crystallization of the Fe‐O‐Mn structure, leading to the formation of abundant oxygen vacancies and surface defect sites. Results indicated that the catalytic performance of FeMnO_x (T₉₀ = 225°C) was significantly superior to that of single‐metal oxides, attributed to the enhanced Mn³⁺ content, O_ads, and oxygen mobility induced by the Fe‐Mn synergistic effect. Systematic characterization confirmed that the strong interaction between Fe and Mn in FeMnO_x reduced the Mn‐O bond strength and optimized the adsorption and activation capabilities of oxygen species. In situ DRIFTS analysis further revealed the unique reaction pathway of FeMnO_x: benzoic acid could be directly converted to maleic anhydride, circumventing the formation of phenol intermediates, thereby reducing the accumulation of by‐products and accelerating the deep oxidation of toluene to CO₂ and H₂O. This research presented a novel strategy for the green synthesis of efficient Fe‐Mn catalysts and provided an innovative approach to the catalytic degradation of toluene.

CeO ₂ ‐H ₂ SO ₄ (C‐S), CeO ₂ ‐TiO ₂ (C‐T), and CeO ₂ ‐TiO ₂ ‐H ₂ SO ₃ (C‐T‐S) were used for the selective catalytic reduction of NO with NH ₃ (NH ₃ ‐SCR). Nearly 100% NO _x conversion of C‐T‐S was achieved at 250°C–450°C. When the concentration of Ce ₂ (SO ₄ ) ₃ was excessively high, it causes tightly binding with Ce ³⁺ ions in CeO ₂ , prevents some Ce ³⁺ ions from effectively participating in redox reactions, and results in the inferior SCR activity. Consequently, C‐T‐S possessed the superior catalytic performance due to the optimal content of sulfates. Furthermore, the presence of NO ₂ facilitated the rapid SCR reaction on C‐T‐S, thereby further enhancing the catalytic activity. Additionally, the formation of Ce ₂ (SO ₄ ) ₃ on C‐T‐S could increase the number of acid sites, particularly Brönsted acid sites, resulting in the improvement of SCR performance. C‐S, C‐T, and C‐T‐S mainly followed the Langmuir–Hinshelwood (L–H).

When preparing lightweight ceramsite using carbide slag, trace amounts of toxic elements are released into the atmosphere due to high-temperature calcination, posing a significant risk to the environment. The real-time monitoring of the released gases is challenging under laboratory conditions while preparing large quantities of ceramsite. Therefore, heating was simulated using experimental data and the FactSage 7.0 thermochemical database to study the release of harmful Al-, C-, H-, S-, and F-containing elements when using carbide slag to prepare lightweight ceramsite. The results indicated that no Al, C, H, S, or F elements were evident in the high-temperature liquid products obtained in a 50 °C to 1150 °C calcination temperature range. Al was present in a solid state with no gaseous products. When the temperature reached 450 °C, CO gas was released and its level increased as the temperature rose. H and S mainly combined into H₂S gas, starting at 250 °C and reaching a peak at 1050 °C. H and F primarily combined into HF, starting at 400 °C. Other F-containing gases mainly included SiF₄ and TiF₃, which began to release at 800 °C and 900 °C, respectively. The release trends of HF, SiF₄, and TiF₃ were consistent with those of CO. This study aimed to conduct an environmental impact and management assessment for the preparation of lightweight ceramsite using carbide slag. The use of raw material carbide slag for the low-cost treatment of tail gas was proposed, which provides theoretical and up-to-date support for greening the application of the process.

Three kinds of three‐dimensional (3D) Mn₂O₃ catalysts with different morphologies (cube, fan‐like structure, and sphere) and various exposed crystal planes were prepared by a hydrothermal method for benzene oxidation. The activity results suggested that sample Mn₂O₃‐Cl with hierarchical cube morphology exhibited a better rate of benzene degradation than the other samples. Mn₂O₃‐Cl exhibited the lowest complete benzene conversion temperature (T₉₀ = 252°C), which was ~48°C lower than that of the Mn₂O₃‐S sample. Meanwhile, the R_m and R_s values of Mn₂O₃‐Cl were 2.71 and 3.21 times, respectively, higher than those of Mn₂O₃‐S. TEM results suggested that morphology has a significant effect on crystal planes. The activity–morphology relationship over the Mn₂O₃ samples was investigated by multiple analytical techniques. It can be concluded that the low crystallinity, superior redox ability, abundant low‐valence Mn ions, and O_latt species in the Mn₂O₃‐Cl catalyst were responsible for its superior catalytic activity.

To investigate secondary pollution issued during the preparation of sintered brick from waterquenched yellow phosphorus slag, the composition of slag was experimentally measured in this study. The thermal conversion process and gas phase products associated with S-, P-, F-, and As-containing species present in the heating system were theoretically calculated by means of thermochemical software FactSage 7.0 and databases. The results showed that F and As were released at 700ºC and the gaseous products contained AsF3. Also, large amounts of F remained in solid CaF2 and Ca10(PO4)6F2. At a calcination temperature of 900ºC, all As was transferred into gaseous AsF3 and S started to convert into gaseous SO2 and SO3. Other data suggested that the released amounts of SO2 and SO3 increased as calcination temperature rose. At calcination temperatures ranging from 100-1000ºC, all P existed as solid Ca10(PO4)6F2. These findings indicated that low calcination temperatures were beneficial for reducing released harmful gases during the production of sintered brick.