Physical Grinding of Prefabricated Co3O4 and MCM-22 Zeolite for Fischer-Tropsch Synthesis: Impact of Pretreatment Procedure on the Dispersion and Catalytic Performance.

To improve the mess-specific activity of Co supported on zeolite catalysts in Fischer-Tropsch (FT) synthesis, the Co-MCM-22 catalyst was prepared by simply grinding the MCM-22 with nanosized Co3O4 prefabricated by the thermal decomposition of the Co(II)-glycine complex. It is found that this novel strategy is effective for improving the mess-specific activity of Co catalysts in FT synthesis compared to the impregnation method. Moreover, the ion exchange and calcination sequence of MCM-22 has a significant influence on the dispersion, particle size distribution, and reduction degree of Co. The Co-MCM-22 prepared by the physical grinding of prefabricated Co3O4 and H+-type MCM-22 without a further calcination process exhibits a moderate interaction between Co3O4 and MCM-22, which results in the higher reduction degree, higher dispersion, and higher mess-specific activity of Co. Thus, the newly developed method is more controllable and promising for the synthesis of metal-supported catalysts.

[Effects of Biochar and Soil Conditioner on Coastal Barren Saline-alkali Soil].

This study aimed to quantify the biological improvement and availability from a soil amendment substance for barren severe saline-alkali soils. A field experiment was conducted to apply biochar (B) and soil conditioner (C) rich in humic substances to pioneer crops and oil sunflower planted in the coastal barren severe saline-alkali area of the North China Low Plain. The six treatments included single or combined application of two-level biochar rates (0 and 1.25 kg·m-2) and three-level soil conditioner rates (0, 0.83, and 1.66 kg·m-2) at the start of the experiment. Soil samples were collected at 30 cm per layer and sampling from 0 to 90 cm after the oil was collected. The results revealed that the application of biochar increased the saline concentration of the 0-30 cm and 60-90 cm soil layers, whereas the soil conditioner significantly decreased the saline concentration of the 0-30 cm soil layers. Neither biochar nor conditioner showed a significant impact on soil pH. Biochar exhibited varying impacts on soil nutrients, that is, significantly inhibiting soil nitrification, which resulted in soil NO3--N decreasing while NH4+-N increased significantly, along with no significant impact on soil organic matter content (SOM) in the 0-90 cm soil profile. The application of soil conditioner exerted positive effects on improving SOM in the 0-30 cm layer and NO3--N in the 0-90 cm soil depth when the conditioner rate was at 1.66 kg·m-2. Either the sole application or the co-application of biomass and conditioner, along with their interaction, exhibited an increasing trend for the NH4+-N, available phosphorus (Olsen-P), and available potassium (Kex) contents, also seen in the 0-90 cm soil profile, although the increase effect for the three nutrients was primarily attributed to biochar. Soil conditioner was more effective in increasing SOM and reducing saline in the 0-30 cm soil layer. The application of a higher amount of conditioner accelerated soil nitrification, whereas biochar was applied essentially as a nitrification inhibitor. Therefore, the co-application of biochar with soil conditioner would be an effective practice for improving soil fertility, preventing soil nitrification, and deterring nitrate leaching, as well as reducing saline for topsoil, which would be a basis for developing soil amendments to control saline and a fertile soil environment for pioneer crops planted in coastal barren severe saline-alkali areas.

[Interactive effects of drought and salt stresses on winter wheat seedlings growth and physiological characteristics of stress-resistance].

In a hydroponic culture, different concentrations of PEG-6000 (0, 8.3%, and 12.6%, W/V) and NaCl (0, 25, and 50 mmol x L(-1) were added to simulate different degrees of drought and salt stresses, aimed to study their interactive effects on the winter wheat (cv. Cang-6001) seedlings growth and physiological characteristics of stress-resistance. The results showed that under the conditions of adding 8.3% and 12.6% of PEG-6000, the addition of 25 mmol NaCl x L(-1) increased the dry matter accumulation and water content in plant, the contents of soluble sugar and soluble protein in leaf and the Na+ content in shoot and root, while decreased the MDA and proline contents in leaf and the K+ content in shoot and root, compared with no NaCl addition. Adding 12.6% of PEG-6000 and 50 mmol x L(-1) of NaCl more inhibited plant growth, compared with no NaCl added. It was suggested that under drought stress, applying definite amount of salt could alleviate the deleterious effects of drought stress on winter wheat seedlings growth.