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A series of Pt catalysts supported on SO42− group modified Al2O3 were synthesized and tested for methane and propane combustion. The introduction of SO42− group promoted the surface acidity but reduced the quantity of exposed surface Pt atoms due to strong coordination effect. The presence of SO42− group significantly promoted the propane combustion reaction but inhibited the methane combustion reaction. It can be inferred that the promotion on propane combustion is ascribed to the enhanced activation of C–C bond (370.3 kJ mol−1) by sulfates. Whereas the sulfates are not favorable for the activation and cracking of C-H bond (439.3 kJ mol−1), and the reduced number of exposed Pt sites results in the activity decrease of methane combustion. [ABSTRACT FROM AUTHOR]

MoO3 promoted Pt/ZrO2 catalysts were prepared by co-impregnation (Pt–Mo/ZrO2) or stepwise impregnation (Pt/Mo/ZrO2 and Mo/Pt/ZrO2) for propane combustion. The impregnation order affects the density of active Pt–MoO3 interfacial sites, in the order of: Pt–Mo/ZrO2 (7.60 μmol gcat−1) > Pt/Mo/ZrO2 (3.40 μmol gcat−1) > Mo/Pt/ZrO2 (1.20 μmol gcat−1). The turnover frequency, TOFPt–MoO3, of Pt–MoO3 interfacial sites is much higher than the TOFPt of Pt active sites (at least 50 folds). Thus, the catalytic activity for propane combustion is in the order of: Pt–Mo/ZrO2 > Pt/Mo/ZrO2 > Mo/Pt/ZrO2 > Pt/ZrO2. Kinetic results illustrate that the MoO3 promotion significantly weakens the strong adsorption of oxygen species on the catalyst and enhances the catalytic activity. The activation energy is reduced the most over the Pt–Mo/ZrO2 catalyst (Ea of the Pt/ZrO2 catalyst: 102.8 ± 4.8 kJ mol−1; Ea of the Pt–Mo/ZrO2 catalyst: only 40.3 ± 1.8 kJ mol−1). [ABSTRACT FROM AUTHOR]

Novel Mn−Eu−Fe catalysts were prepared via co‐precipitation method for NOx removal by selective catalytic reduction with NH3 (NH3−SCR). The Mn−Eu−Fe(1)‐500 catalyst possessed the highest level of low‐temperature activity, giving 98 % NO conversion at 100 °C. This catalyst also exhibited excellent H2O resistance capacity, even at a high gas hourly space velocity (GHSV) of 75,000 h−1. The NO conversion still maintained at approximately 90 % in the presence of 15 % H2O at 230 °C after 50 h, and the adverse effects of H2O could be quickly eliminated after the removal of H2O. Detailed characterization and analysis indicated that strong interactions among Mn, Eu and Fe resulted in the excellent low‐temperature SCR activity and H2O resistance of the Mn−Eu−Fe(1)‐500 catalyst. The strong interactions lead to larger specific surface area, higher concentrations of Mn4+, Fe3+ and Oα; improved redox properties, increased acid sites and acid strength, and more adsorption amounts of NO/NH3 in the presence of H2O. The Mn−Eu−Fe(1)‐500 catalyst is a potential future catalyst for low‐temperature NOx removal derived from high‐H2O‐content flue gases of natural gas combustion. [ABSTRACT FROM AUTHOR]

• Advanced progress of electrochemical synthesis of high-value derivatives from HMF is reviewed. • The structure-activity relationship towards different materials is revealed. • Challenges and prospects for electrochemical conversion of HMF are discussed. With application of renewable energy and mild synthesis condition, the electrochemical conversion of 5-hydroxymethylfurfural (HMF) into high-value chemicals via electrocatalytic oxidation/reduction reaction recently draws more attentions. For example, the oxidation products of HMF such as 2,5-furandicarboxylic acid (FDCA), 2,5-dihydroxymethyifuran (HMFCA), 2,5-diformylfuran (DFF), and maleic acid (MA) are important industrial products. The reduction products of HMF are also widely used, 2,5-dimethylfuran (DMF), 2,5-dihydroxymethyifuran (DHMF), 2,5-dihydroxy methyl tetrahydrofuran (DHMTHF), 2,5-hexanedione (HD), and 5,5′-bis (hydroxymethyl) hydrofuroin (BHH) have been reported and attracted widespread attention. However, some problems including uncertain mechanism, excessive activation power, low catalytic activity, and high barrier are existed and need to be urgently solved. This review aims to provide a summary of advances in electrochemical synthesis of high-value derivatives from HMF. Firstly, the concept and reaction mechanisms for electrocatalytic oxidation/reduction of HMF are introduced detailly. Secondly, different kinds of electrocatalysts for the electrochemical conversion of HMF and their structure-activity relationship are systematically investigated. Moreover, the potential challenges and prospects for electrochemical conversion of HMF are also proposed. This work provides an important guidance for constructing efficient electrocatalysts toward electrochemical conversion of HMF. Recent advances in electrocatalyst synthesis for conversion of 5-hydroxymethylfurfural into high-value derivatives. [Display omitted] [ABSTRACT FROM AUTHOR]

• This work reviews tandem mechanism of electrochemical CO 2 RR. • 2.Copper-based and other copper-free tandem catalysts for CO 2 RR is summarized. • Challenges, opportunities and prospects of tandem catalysts for CO 2 RR are proposed. Electrocatalytic CO 2 reduction reaction (CO 2 RR) is one of the important ways to achieve the goal of CO 2 utilization and synthesizing high-value products. Electrochemical CO 2 RR involves multiple electron-proton transfer steps, resulting in low yield and low selectivity. *CO is considered as the key intermediate, the process of CO 2 RR can be divided into a tandem step of CO 2 -to-CO and CO-to-C 2+. To promote kinetic rate of whole reaction and improve faraday efficiency of the product, tandem catalysts are constructed. Here, the recent advances in application of tandem catalyst for electrocatalytic CO 2 RR are reviewed for three aspects: (1) tandem mechanism of electrochemical CO 2 RR; (2) copper-based tandem catalysts as well as other copper-free tandem catalysts for electrochemical CO 2 RR; (3) challenges, opportunities and prospects of tandem catalysts for CO 2 RR. This review provides a comprehensive understanding tandem electrocatalytic mechanism of tandem catalysts for CO 2 RR and important guidelines for the field of electrocatalysis. Copper-based and other copper-free tandem catalysts for electrocatalytic CO 2 reduction [Display omitted] [ABSTRACT FROM AUTHOR]