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Manganese-based catalysts supported by TiO 2 (MnO 2 /TiO 2) show good deNO x performance at low temperature. However, the microscopic impact mechanism of poisonous substances such as K and SO 2 on the deNO x of the MnO 2 /TiO 2 catalyst is a grey area. In this work, the poisoning mechanism of K and SO 2 coexistence on the deNO x of the MnO 2 /TiO 2 catalyst was explored by using a density functional theory combined with experimental methods. SO 2 has low adsorption performance on the MnO 2 /TiO 2 (001) surface, while it can be oxidized to form SO 3 , and it will react with the catalyst to form sulfates. K poisoning makes NH 3 and NO molecules more difficult to be adsorbed on the MnO 2 /TiO 2 (001) surface. However, when SO 2 is introduced on the catalyst surface with K poisoning, it can interact with K and change the charge transfer from K to the catalyst surface, alleviating the K poisoning of the catalyst. These results contribute to the understanding of the mechanism of K and SO 2 co-poisoning on the deNO x of Mn-based catalysts at a microscopic level, and provide guidance for designing Mn-based catalysts with high anti-poisoning ability. [Display omitted] [ABSTRACT FROM AUTHOR]

Microbial electrolysis cells (MECs) is one of the promising biohydrogen production technologies for which low‐cost cathode materials are required and developed to propel the rapid development of MECs. Herein, the preparation of a low‐cost Ce0.1−Ni−Y composite is reported by using Y zeolite as carrier loaded with nickel (Ni) and cerium (Ce) as active components and its prominent electrochemical performance. The XPS analysis reveals that strong electronic interaction between Ni and Ce makes a great contribution to the electrochemical performance enhancement. The Ce0.1−Ni−Y with a peak current density of 39.8 A⋅m−2 in LSV, Tafel slope of 40.81 mV⋅dec−1, ECSA of 34.3 and hydrogen yield of 0.312±0.013 m3⋅m−3 d−1 are significantly superior to that of its parent Ni−Y counterpart and rival the performance of commercially Pt/C, which renders it a very promising hydrogen evolution catalyst for MECs. [ABSTRACT FROM AUTHOR]

Abstract: A Mo2C and an alumina-supported Mo2C catalysts were prepared and their catalytic performance for the direct decomposition of NO to N2 and O2 was evaluated in a continuous-flow microreactor. The structural properties of the catalysts have been studied using X-ray diffraction as well as BET surface area measurement. The results show that the bulk molybdenum carbide and the Mo2C/Al2O3 catalysts exhibit an excellent catalytic activity for NO direct decomposition. There is a stronger interaction between the β-Mo2C phase and γ-Al2O3 support in the Mo2C/Al2O3 catalysts when Mo content is higher. It is suggested that the base sites of Mo2C and Mo2C/Al2O3 catalysts may have played an important role in catalyzing the decomposition of NO. [Copyright &y& Elsevier]

Ag/CeO2 catalyst is synthesized by hydrothermal method, which has been studied under the effects of different catalyst content, ash and Ag load through activity and characterization tests. Ag loading increases the catalytic activity of CeO2, and the peak combustion temperature of soot decreases by 74 °C. The catalytic effect of Ag/CeO2 is affected by catalyst content, Ag load and ash content. The optimum mass ratio of soot/catalyst is 1/10, and 10 mass% is the saturation value of Ag loading at CeO2. Ash inhibits the promoting effect of Ag/CeO2 in the oxidation process of soot. This study provides a theoretical basis for the industrial application of Ag/CeO2 catalyst in gasoline engine and also provides a research idea for the low-temperature oxidation of soot. [ABSTRACT FROM AUTHOR]

[Display omitted] • Adsorption behavior of gas molecules at the main active sites adjacent to Pb and Zn and the doping sites were revealed. • Pb and Zn dopings have a negative effect on the generation of *NH 2 and *O. • The detrimental effect on the deNO x of Pb is severer than that of Zn. • The inhibition mechanisms of Pb and Zn on the deNOx were discussed. Mn-based catalysts are promising materials for the removal of NO x by NH 3 -SCR reaction. Heavy metals can cause the deactivation of deNO x of catalysts. However, the inactivation mechanism of catalysts requires further research. In this paper, the effects of Pb and Zn doping on the deNO x reaction over the β-MnO 2 catalyst were investigated by the DFT method, and the poisoning mechanism of heavy metals on the catalyst was revealed. Pb and Zn can not only inhibit the adsorption of NH 3 and O 2 at the peripheral sites, but also weaken the adsorption properties of NH 3 at the doping sites, leading to a decrease in the activity of the β-MnO 2 catalyst. Meanwhile, Pb and Zn can limit the formation and decomposition of *NH 2 NO intermediates, which is detrimental to the SCR reaction. In addition, the production of hydroxyl groups is restricted due to Pb and Zn preventing the formation of *H and *O. Although Pb and Zn can make the conversion of hydroxyl groups to *H 2 O easier, it is not enough to compensate for the restricted *H 2 O generation caused by the large reduction in the number of hydroxyl groups, and the deNO x reaction is ultimately inhibited. [ABSTRACT FROM AUTHOR]

• The redispersion of Pt on γ-Al 2 O 3 surface was studied via DFT simulation. • The process was divided into two steps: the evaporation and capture of Pt species. • Oxychlorination can reduce the minimum temperature requirement for Pt evaporation. • Oxychlorination can also increase the maximum allowable temperature for Pt capture. • A thermodynamically favored redispersion process can be achieved via oxychlorination. The redispersion of metal particle on the catalyst support is closely related to the stable operation as well as the regeneration process of catalysts. Pt/γ-Al 2 O 3 is an important catalytic system for several industrial processes. Sintering of metal particles is usually a big challenge for Pt/γ-Al 2 O 3 , and the redispersion strategies have been developed to reverse the sintering process. In this work, the redispersion of Pt on γ-Al 2 O 3 surface was studied via molecular simulation based on the density functional theory (DFT). The redispersion process was divided into two steps, the evaporation of Pt atom from the Pt cluster and the capture of Pt species over the Al 2 O 3 surface. The result shows that the addition of HCl during the redispersion is helpful to both of the processes. The oxychlorination can reduce the minimum temperature of the Pt evaporation and increase the maximum allowable temperature of the capture of Pt species, leading to a thermodynamically favored redispersion process. The result explained the mechanism of the redispersion behavior of Pt on the γ-Al 2 O 3 support during oxychlorination for the Pt/γ-Al 2 O 3 catalyst. The method can also be extended to the study on the redispersion of other catalytic systems. [ABSTRACT FROM AUTHOR]

A novel SnO 2 -based catalyst doped with Cu and N for highly efficient photoelectrochemical reduction CO 2 to formate was synthesized by a two-step process of facile hydrothermal and pyrolysis methods. It is demonstrated that introducing Cu and N significantly enhances the catalytic activity for CO 2 reduction, which is attributed to the defect levels that narrow the band gap to accelerate the charge transfer. • Co-doping of (Cu, N) generated defect energy levels to improve catalysis performance. • The doping of (Cu, N) significantly increased oxygen vacancies in SnO 2 based catalysts. • The optimal doping amount of 7 mol% resulted in a maximum Faraday efficiency of 54.97%. Electrocatalytic and photocatalytic reductions of CO 2 into valuable chemicals or fuels have been considered a compelling strategy for environmental remediation and renewable energy conversion. In this field, SnO 2 based materials have been widely applied as a promising electrocatalysts in the conversion of CO 2 to formate, but the inferior catalytic efficiency is still the severe barrier for the application. In this study, a novel SnO 2 -based catalyst with Cu and N co-doping was designed for efficient and high-selective photoelectroreduction of CO 2 into formate. XRD, FT-IR and XPS analyses demonstrated that (Cu, N) was doped into the lattice of SnO 2 via replacing Sn and O, resulting the significant increase in the amount of oxygen deficiency from 27.18% to 36.72%. CV, LSV and EIS measurements proved that the (Cu, N) doping dramatically improved the photoelectrocatalytic performance of SnO 2 based electrocatalysts for CO 2 reduction. When the co-doping amount of (Cu, N) was 7 mol%, the Faradaic efficiency reached 54.97% with a lowest charge-transfer resistance and a fastest electron transfer rate. Furthermore, the DFT calculations revealed that the co-doping of Cu and N brought about the defect levels to narrow the band gap for the acceleration of the charge transfer, thereby improved the performances in electroreduction as well as photoreduction of CO 2. [ABSTRACT FROM AUTHOR]