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Energy shortage and global warming caused by the extensive use of fossil fuels are urgent problems to be solved at present. Photoreduction of CO2 is considered to be a feasible solution. The ternary composite catalyst g‐C3N4/Ti3C2/MoSe2 was synthesized by hydrothermal method, and its physical and chemical properties were studied by an array of characterization and tests. In addition, the photocatalytic performance of this series of catalysts under full spectrum irradiation was also tested. It is found that the CTM‐5 sample has the best photocatalytic activity, and the yields of CO and CH4 are 29.87 and 17.94 μmol g−1 h−1, respectively. This can be ascribed to the favorable optical absorption performance of the composite catalyst in the full spectrum and the establishment of S‐scheme charge transfer channel. The formation of heterojunctions can effectively promote charge transfer. The addition of Ti3C2 materials provides plentiful active sites for CO2 reaction, and its superior electrical conductivity is also favorable for the migration of photogenerated electrons. [ABSTRACT FROM AUTHOR]

The salts of alkali earth metals (Ca and Mg) in fly ash have a deactivation effect on SCR catalyst. In this study, the poisoning effect of Ca and Mg on Mn/TiO2 catalyst was investigated and explained based on experimental and characterization results of BET, XRD, H2-TPR, NH3-TPD and XPS. It was found that the deactivation effect of Ca is more obvious than that of Mg. The results showed that the drop of redox ability and Brønsted acidity, and the decrease of active oxygen species led to the decrease of Ca-Ce/TiO2 and Mg-Ce/TiO2.

The photocatalytic reduction of CO2 to hydrocarbons is expected to simultaneously alleviate the energy crisis and greenhouse effect. Herein, the ternary BiOCl/C/Cu2O catalysts with different mass ratios were compounded using a simple hydrothermal method, revealing better photocatalytic activity than the monomer. In the absence of sacrificial agents and photosensitizers, 25% BiOCl/C/Cu2O showed optimal photocatalytic performance. The CO and CH4 yields over 25% BiOCl/C/Cu2O reached 26.77 and 9.86 μmol g−1 h−1, which is 2.9 and 8.7 times higher than that of the pristine Cu2O, respectively. The ameliorative activity can be attributed to the construction of the Z-scheme heterostructure and carbon layer, which are conducive to the transfer and separation of photogenerated carriers. This study offers valuable references for the design and investigation of a Z-scheme heterojunction using a carbon layer as an electron transfer medium. [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of CO2 to hydrocarbons is expected to simultaneously alleviate the energy crisis and greenhouse effect. Herein, the ternary BiOCl/C/Cu2O catalysts with different mass ratios were compounded using a simple hydrothermal method, revealing better photocatalytic activity than the monomer. In the absence of sacrificial agents and photosensitizers, 25% BiOCl/C/Cu2O showed optimal photocatalytic performance. The CO and CH4 yields over 25% BiOCl/C/Cu2O reached 26.77 and 9.86 μmol g−1 h−1, which is 2.9 and 8.7 times higher than that of the pristine Cu2O, respectively. The ameliorative activity can be attributed to the construction of the Z-scheme heterostructure and carbon layer, which are conducive to the transfer and separation of photogenerated carriers. This study offers valuable references for the design and investigation of a Z-scheme heterojunction using a carbon layer as an electron transfer medium. [ABSTRACT FROM AUTHOR]

Herein, the origin and evolution mechanism of N2O formation over the MnFeOx spherical catalyst were investigated in detail, accompanied by a comparison analysis of pristine MnOx and FeOx catalysts. The results showed that the MnFeOx catalyst possessed higher catalytic activity but poorer N2 selectivity than the sole oxide catalysts, and the N2O concentration could even reach 300 ppm over 175 °C. Further activation tests under separate NH3/NO oxidation conditions revealed the N2O accumulation of the MnFeOx catalyst that was primarily derived from the NSCR pathway below 150 °C and then gradually turned to NH3 over-oxidation with temperature. The coupling of Mn and Fe cations induced electron migration and released more Mn4+ and Os, contributing to the upgraded redox capacity, which served as the inherent motivation of high activity but poor N2 selectivity over the MnFeOx catalyst. For the NH3 over-oxidation pathway, both gaseous O and catalyst oxygen acted as the oxidizers, and the double –NH2/NH species with the assistance of O was deemed as the restricted step for N2O generation. For the NSCR pathway, the byproduct N2O was generated through both E–R and L–H mechanisms, and the former contributed to more N2O. In addition, the kinetic analysis further verified the obtained conclusions. Finally, a possible mechanism model of N2O origins over the MnFeOx catalyst was proposed. [ABSTRACT FROM AUTHOR]