摘要: Recently, organosulfur removal from liquid petroleum fuels is very significant aspect of environment protecting and fuel cell requests. Therefore, improved approaches to remove sulfur are still essential. In the present work, a simple catalytic oxidative desulfurization (CODS) system for Iraqi gasoil fraction has been successfully developed using CuO-ZnO nanocomposites as catalysts, and H2O2 as oxidant under microwave irradiation. The main reaction parameters influencing sulfur conversion including microwave power, irradiation time, catalyst dosage and H2O2 to gasoil volume ratio have been investigated. The CuO-ZnO nanocomposites was synthesized with different weight ratios and characterized by XRD, FE-SEM, AFM and BET surface area methods. The results reveal that, high sulfur conversion (93%) has been achieved under suitable conditions of microwave CODS as follows:microwave power of 540 W, irradiation time of 15 min, catalyst dosage of 8 g/L (0.4 g), and H2O2:gasoil volume ratio of 0.3. The catalyst reusability shows that the synthesized catalyst can be reused five times without an important loss in its activity.
摘要: Developing cost-effective electrocatalysts for oxygen evolution reaction (OER) in basic media is critical to hydrogen production from renewable energy. Herein, in-situ electrodeposited flower-like NiFeOxHy and NiFeOxHy/rGO composite electrocatalysts on Ni foam for OER are reported. The active sites of the flower-like electrocatalysts are increased significantly due to the enhanced NiFeOxHy surface areas and numerous exposed layered edges and edge defects. Reduced graphene oxide (rGO) has been introduced to fabricate NiFeOxHy/rGO composite film, further improving the conductivity and OER performance of the flower-like NiFeOxHy. The optimized NiFeOxHy/rGO exhibits superior OER performance with a Tafel slope of 29.11 mV/decade, an overpotential of 200 mV at 10 mA/cm2 in 1 mol/L KOH and favorable long-term stability.
摘要: Nd-Co3O4 catalysts were prepared by hydrothermal and co-precipitation methods to catalyze the decomposition of N2O. The catalysts prepared by hydrothermal method showed higher activity. Among the hydrothermal Nd-Co3O4 catalysts, the catalyst with Nd/Co molar ratio of 0.01 had higher activity. 0.01Nd-Co3O4 catalyst was then impregnated by K2CO3 solution to prepare K-modified catalyst. The catalysts were characterized by means of X-ray diffraction (XRD), nitrogen physisorption, scanning electrons microscopy (SEM), X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H2-TPR), and oxygen temperature-programmed desorption (O2-TPD). The results show that Nd-Co3O4 and K-modified catalysts exhibit spinel structure. In contrast to bare Nd-Co3O4, the K-modified catalyst with higher activity is due to its weaker strength of Co-O bond and easier desorption of surface oxygen species. In addition, over 90% conversion of N2O can be reached over 0.02K/0.01Nd-Co3O4 at 350 ℃ for 40 h under the co-presence of oxygen and steam in feed gases.
