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Summary: Soot particulate emitting from diesel engines are serious to both human health and environment. Efficient catalyst is vital in diesel particulate filter technology to decrease soot oxidation temperature. Cu1−xKxFe2O4 (x = 0, 0.05, 0.1, and 0.15) catalysts are synthesized and analyzed with XRD, Raman, BET, SEM, TEM, TG, EDS, XPS, catalytic activity tests, and kinetic analysis. The results suggests that many factors affect the catalytic activity, and the contents of oxygen vacancies are dominant. A large amount of oxygen vacancies which facilitate to the soot oxidation are created with the assistance of K+, and they increase with the increasing doping contents. Excessive surface concentration of K+ may lead to the partially covering of active sites of the catalysts. Therefore, Cu0.9K0.1Fe2O4 catalyst exhibits the best catalytic activity in soot oxidation, which decreases the Tmax of soot by 279°C. This decrease makes it highly promising for application in diesel particulate filter. [ABSTRACT FROM AUTHOR]

Summary: Stabilities of activities and physicochemical properties for catalyst materials are crucial for continuous gas‐fuel production from catalytic gasification of organics by thermochemical processes. In this paper, low‐cost Ni catalysts supported on La‐, Ce‐, and Mg‐promoted Al2O3 and ZrO2 were prepared and compared in terms of long‐term catalytic activity, property stability, and coke‐resistant ability for H2 production from steam reforming (SR) of glycerol. The SR reactions were performed in a continuous fixed‐bed reactor at 500°C for 24 hours using 5 wt% glycerol as the feed. Techniques including XRD, N2 adsorption/desorption, SEM/TEM, and TGA were applied for characterizing both the fresh and used catalysts. Results illustrate that prepared by two‐impregnation mothed, the La, Ce, and Mg promoters effectively suppressed the strong interaction of Ni and Al2O3 to avoid NiAl2O4 formation during the preparation process. The modified Ni/Al2O3 catalysts contained very fine Ni crystals (5‐8 nm) which greatly promoted the carbon gasification efficiency of the SR reaction from 3% without the use of a catalyst to 65‐87%, with the H2 yield increased from 0.5 to 3‐5 mol/mol. The catalyzed gas products were composed of about 67% H2 and 31% CO2. The La‐promoted Ni/Al2O3 catalyst achieved the highest activity and the most stable crystalline structure for 24‐hour reaction. The Ce‐promoted Ni/ZrO2 catalyst obtained stable but much less carbon gasification efficiency (approximately 30%) due to its large Ni crystals (36 nm) over the bulk ZrO2 supports. [ABSTRACT FROM AUTHOR]

Summary: Chemical looping steam reforming (CLSR) of acetic acid as bio‐oil model compound is a suitable way to produce hydrogen‐rich syngas. The LaNiO3 and LaNi0.8M0.2O3 (M = Fe, Co, Mn, and Cu) perovskites were prepared via the sol‐gel method. The perovskites were characterized by X‐ray diffraction (XRD), thermogravimetry (TG), and test activity of hydrogen‐rich syngas in a fixed bed. XRD and TG results showed that the coke generation on LaNi0.8Fe0.2O3 needs a lower decomposition temperature, and a stable structure was appeared after reaction. The activity order of hydrogen‐rich syngas on five types of perovskite is LaNi0.8Fe0.2O3 > LaNi0.8Co0.2O3 > LaNiO3 > LaNi0.8Mn0.2O3 > LaNi0.8Cu0.2O3 at 650°C, mole ratio of steam/carbon (2:1), and sample mixture flow (GHSV = 34 736 g of feed/(g catalyst h)). The CLSR of acetic acid with LaNi0.8Fe0.2O3 at GHSV = 43 992 g of feed/(g catalyst h) showed good stability. Correlated to experimental results, the adsorption energy of steam and acetic acid on five types of perovskite were calculated using density functional theory (DFT). The adsorption energy of steam (−0.61 eV) and acetic acid (−0.93 eV) of LaNi0.8Fe0.2O3 is maximum. This value of DFT calculation is well explained in the experimental results. [ABSTRACT FROM AUTHOR]

SUMMARY An investigation on the chemical looping reforming of ethanol process using Gibbs free energy minimization method was performed. It is found that the temperature, oxygen/ethanol molar ratio (OER), and pressure have pronounced influences on the product yields in chemical looping reforming of ethanol process. The ethanol conversion and H2 yield are 100% and 2.25 mol mol−1 ethanol, respectively, at 700 °C, OER of 1 and 1 atm. The higher temperatures promote H2 and CO production, but the higher pressures and OERs have negative effect on the H2 and CO generation. Favorable operation conditions are 1 atm, 700 °C, and OER = 1. The experimental tests were carried out in a fixed bed using a Cu-based oxygen carrier prepared by impregnation method. Working at 1 atm, the H2 concentration increased with an increase in temperature; however, it remained approximately with an increase in gas hourly space velocity. The H2/CO molar ratio was between 3 and 5 in the period of 0-30 min at 1 atm and 700 °C. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY Chemical-looping ethanol reforming with carbon dioxide capture is proposed. It combines chemical-looping reforming and carbon dioxide capture for pure hydrogen generation from ethanol with inherent separation of carbon dioxide. A thermal analysis of the process using NiO oxygen carrier is performed by simulating reactions using the Gibbs energy minimization method. The promising systems are investigated further with respect to temperature, NiO/C2H5OH molar ratio, CaO/C2H5OH molar ratio and pressure changes as well as possible carbon formation in the reformer. Favorable operation conditions in the presence of CaO are: pressures around 3 atm, reactor temperatures around 850 K, NiO/C2H5OH molar ratio = 3 and CaO/C2H5OH = 3. The H2 yield and thermal efficiency with CaO addition are higher than that without CaO addition, showing that the addition of a CO2 sorbent in the process increases the H2 production. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]