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As-synthesized Cu3PdN nanocrystals displayed high faradaic efficiency and selectivity for nitrate-to-ammonia conversion. The excellent performances can be attributed to the charge redistribution in Cu3PdN as a result of modulations of the electronic structures of Pd and Cu atoms, which altered the adsorption activation energy of the intermediates during the nitrate reduction reaction process. [ABSTRACT FROM AUTHOR]

Driven by the demand for accurate intrinsic kinetics for the prediction of the combustion rate of purely fired Zhundong coal (ZDC) in a slag tapping boiler, the surface activation function (SAF) and intrinsic kinetic parameters of two types of rapid-pyrolysis ZDC chars were revealed via the isothermal and nonisothermal thermogravimetric analysis methods. The isothermal kinetic results show that the activation energy (E), reaction order and SAF of these two chars were the same, at 146 kJ/mol, 0.78 and X 0.44 (1 – X)−0.48, respectively. Therefore, the difference in the intrinsic reaction rate between these two chars was caused only by the different pre-exponential factors, which are mainly influenced by the specific surface area and catalytic elements in char ash. Nonisothermal kinetic parameters were obtained via the isothermal model-fitting method (ISOM), thereby using the isothermal SAF to fit the nonisothermal data at different heating rates (β s). The results indicate that the E values of the two chars were 148.95 ± 3.12 kJ/mol and 146.16 ± 1.66 kJ/mol, indicating that β has little influence on E. These measured values are consistent with the isothermal E values, so the ISOM is suitable for the determination of the nonisothermal kinetics of rapid-pyrolysis char combustion. • Intrinsic combustion kinetics of rapid-pyrolysis Zhundong coal chars were obtained. • Different chars have the same E , reaction order and surface activation function. • Catalytic elements have a positive effect on A but have little influence on E. • The heating rate has little influence on E of rapid-pyrolysis char combustion. • ISOM is suitable to describe the combustion kinetics of rapid-pyrolysis char. [ABSTRACT FROM AUTHOR]

• Hydrothermal carbonization (HTC) was performed to upgrade the sawdust. • Hydrochar characterizing and kinetics analysis were conduted. • The HTC temperature plays an important role in hydrochar performance. • The CO 2 , CO, CH 4 , and H 2 O were main gas products from hydrochar pyrolysis. This work intends to reveal the pyrolysis behavior of hydrochar from hydrothermal carbonization (HTC) of pinewood sawdust. The elemental analysis and pyrolysis test were performed to study the effect of HTC on hydrochar performance. The elemental analysis indicates that the fuel properties could be highly upgraded by the HTC process. Compared with raw biomass (48.10 % and 19.12 MJ/kg), the carbon content and heating value was improved to 69.05 % and 26.66 MJ/kg for HTC-260. The atomic ratios H/C and O/C were decreased from 1.31 to 0.90 and 0.72 to 0.26, respectively, by means of dehydration and decarboxylation in the HTC process. The pyrolysis test implies that the thermal stability of hydrochars has been improved by the HTC. The hydrochars decomposition temperature and the pyrochar yields became higher and higher with the HTC temperature. For the HTC-260, the pyrochar yield was increased from 24.4%–53.02% at a pyrolysis temperature of 800 ºC. According to the TGA-FTIR, the main gas products were CO 2 , CO, CH 4 , and H 2 O. Higher HTC temperature promoted more CH 4 production due to the devolatilization, decarboxylation, dehydration and polymerization occurred in the HTC process. 240–260 °C could be considered as a good option to maximize the energy efficiency when taking the HTC as a pretreatment procedure over thermal drying or torrefaction. All these results indicate the HTC is promising to upgrade high-moist biomass for multi-value-added products. [ABSTRACT FROM AUTHOR]