Partial oxidation

About: Partial oxidation is a research topic. Over the lifetime, 8261 publications have been published within this topic receiving 205069 citations.

Reverse microemulsion synthesis of nanostructured complex oxides for catalytic combustion

Abstract: Catalysts play an important role in many industrial processes, but their use in high-temperature applications-such as energy generation through natural gas combustion, steam reforming and the partial oxidation of hydrocarbons to produce feedstock chemicals--is problematic. The need for catalytic materials that remain stable and active over long periods at high operation temperatures, often in the presence of deactivating or even poisoning compounds, presents a challenge. For example, catalytic methane combustion, which generates power with reduced greenhouse-gas and nitrogen-oxide emissions, is limited by the availability of catalysts that are sufficiently active at low temperatures for start-up and are then able to sustain activity and mechanical integrity at flame temperatures as high as 1,300 degrees C. Here we use sol-gel processing in reverse microemulsions to produce discrete barium hexa-aluminate nanoparticles that display excellent methane combustion activity, owing to their high surface area, high thermal stability and the ultrahigh dispersion of cerium oxide on the their surfaces. Our synthesis method provides a general route to the production of a wide range of thermally stable nanostructured composite materials with large surface-to-volume ratios and an ultrahigh component dispersion that gives rise to synergistic chemical and electronic effects, thus paving the way to the development of catalysts suitable for high-temperature industrial applications.

Synthesis of ethylene and ethane by partial oxidation of methane over lithium-doped magnesium oxide

Abstract: The partial oxidation of methane into more useful chemicals such as methanol, ethylene and benzene has been investigated extensively, although yields for these products have been poor1–4. Moreover, in several of these processes the required oxidant is N2O rather than O2. Recent work5 in our laboratory has demonstrated that lithium-doped magnesium oxide (Li/MgO) in the presence of O2 has high activity for abstracting H from CH4 to form ·CH3 radicals. This suggests that C2H6 and C2H4 (C2 compounds) are produced by a coupling between two gaseous ·CH3 radicals formed on this catalyst. We report here our success in converting CH4 to C2 compounds in high yields in conventional catalytic conditions.

Selective anaerobic oxidation of methane enables direct synthesis of methanol

Abstract: Direct functionalization of methane in natural gas remains a key challenge. We present a direct stepwise method for converting methane into methanol with high selectivity (~97%) over a copper-containing zeolite, based on partial oxidation with water. The activation in helium at 673 kelvin (K), followed by consecutive catalyst exposures to 7 bars of methane and then water at 473 K, consistently produced 0.204 mole of CH3OH per mole of copper in zeolite. Isotopic labeling confirmed water as the source of oxygen to regenerate the zeolite active centers and renders methanol desorption energetically favorable. On the basis of in situ x-ray absorption spectroscopy, infrared spectroscopy, and density functional theory calculations, we propose a mechanism involving methane oxidation at CuII oxide active centers, followed by CuI reoxidation by water with concurrent formation of hydrogen.