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The catalytic NO removal efficiencies of MnFeOx/SiO2 catalysts with different Fe/Si were compared and studied. The reaction pathway analysis of NH3-SCR on the surface of MnFeOx/SiO2 catalyst was performed based on DFT calculations. The experimental results of catalytic activity show that the addition of an appropriate amount of iron oxide has significant improvement for the NO conversion from 240 °C to 330 °C and the N2 selectivity from 150 °C to 330 °C. The XRD test also shows that the addition of iron oxide can greatly improve the dispersion of MnO2. In addition, DFT calculations indicate that the main process of N2 formation is the NH2NO decomposition and N-NO reaction. The N-NO reaction to form N2 is a unique reaction pathway possessed by MnFeOx/SiO2, which is the main reason for the high NO conversion and good N2 selectivity of MnFeOx/SiO2 catalyst and shows good synergy between manganese oxide and iron oxide.

Firstly, the polyvinyl alcohol/polyacrylic acid double network hydrogels were prepared by physical and chemical double cross-linking, then polyethylene glycol, chitosan, and hydroxypropyl methyl ce...

The low-temperature catalytic NO removal efficiencies of catalysts with two different manganese precursors, manganese acetate (αMA catalyst) and manganese nitrate (αMN catalyst), were compared and studied. The NH3-SCR of NO tests using these catalysts were carried out in a self-made reaction device to measure the catalytic activity of the catalysts. Moreover, the reaction pathway analysis of NH3-SCR of NO on the surface of MnO2/SiO2 catalyst and Mn2O3/SiO2 catalyst were performed based on DFT calculations individually. The experimental results show that the NO conversion of αMN catalyst is higher than the αMA catalyst at low temperature (

Copper slag, an important by-product of the copper smelting process, is mainly composed of 2FeO SiO2, Fe3O4, and SiO2. Due to the sufficient metal oxides, copper slag is regard as a potential oxygen carrier (OC), which can be applied in chemical looping technology. This research proposed to use the granulated copper slag particles as precursor to produce oxygen carrier. Through this method, waste heat of the high-temperature slag can be fully recovered, eliminating the complicated copper slag pretreatment process. In this paper, the reactivity of granulated copper slag after redox calcination was studied by X-ray diffractometer (XRD) and Scanning Electron Microscope (SEM), the highest reactivity occurred at 1,000°C. In addition, the oxygen release and absorption performance of OC were tested in thermal-gravimetric (TG). According to theoretical calculations, the mass loss caused by oxygen release accounts for 70.57% of the total loss and the mass reached by 4.2% at 1,000°C in oxygen absorption experiment. The copper slag modified through calcining in redox condition was proved to be a promising oxygen carrier in chemical looping process. Furthermore, the performance research on OC also provided theoretical references for the operating paraments of OC circulating between air reactor and fuel reactor in practical chemical looping processes.

The key bottleneck problem of chemodynamic therapy (CDT) is that the efficiency depends heavily on an acidic chemical environment. However, there is a sufficient blood supply on the surface of solid tumours, resulting in neutral-pH surface regions, strongly reducing the effectiveness of CDT. In this study, chelating complex ferrous-cysteine–phosphotungstate nanoparticles (FcPWNPs) are synthesized to serve as new CDT nanoagents that break through the limitation of a neutral pH, ensuring CDT efficiencies at both an acidic and neutral pH. The CDT efficiency is increased by introducing cysteine and phosphotungstate, which form an Fe chelating complex to inhibit the formation of inert Fe(OH)x, and accelerate electron transfer between ferric and ferrous ions, respectively. Due to this ferrous chelating strategy and associated electron transfer property, the FcPWNPs can destroy cancer cells from the neutral-pH tumour surface to the acidic interior, thus realizing a complete CDT cancer therapy.

The catalyst is the core of the NH3-SCR NOx removal process, and sulfur resistance is important performance to ensure its stability and efficiency. The γ-Fe2O3 catalyst has great NOx removal efficiency but its sulfur resistance need to be enhanced to meet the needs of development of Fe based catalyst. In this paper, the sulfur resistance of γ-Fe2O3 and Ce/Mn doped catalyst was studied by quantum chemistry and DFT, and this study can reveal the adsorption process of sulfur oxides on the catalyst surface and the decomposition of surface sulfate. The result shows that the SO2 and SO3 prefer to be adsorbed on the Ce sites and let more Fe active sites exposed to participate NH3-SCR process, but the Mn doping hardly works on improving adsorption. Moreover, Ce doping can effectively decrease the activation energy of the decomposition of ammonium sulfate and promote its decomposition on the catalyst surface, but Mn doping almost cannot improve the decomposition of ammonium sulfate on the catalyst surface. Therefore, doping Ce on γ-Fe2O3 catalyst can effectively improve the sulfur resistance of the catalyst, while Mn has little effect.

The surface reaction process of γFe2O3 catalyst for NOx removal with NH3 was studied by the first principles and density functional theory. The results show that the NH3 molecule is easily adsorbed on the surface of the catalyst, then dehydrogenated to produce NH2, NH and other products, yet most of the products are NH2 since the activation energy barrier from NH2 to NH is high under anaerobic condition. The next main step is that NH2 reacts with gaseous NO to generate NH2NO intermediate products, and then it decomposes to N2 and H2O. The NH3 dehydrogenation is the rate determining step with the activation energy barrier of 88.040 kJ/mol. However, the NH fragment will be formed when oxygen exists since the activation energy barrier from NH2 to NH reduces under aerobic condition. After its formation, the NH fragment will combine with NO to yield NHNO and decomposes to N2 and hydroxyl. In addition, NO2 can be produced on the surface by the absorbed NO reacting with an active O atom, and the NO2 can carry out fast SCR process. Otherwise, the N2O is not easily formed on the surface of γFe2O3 catalyst which means that the catalyst has good selectivity.