The thermal decomposition of CO2 to CO and O2 is a potential route for the consumption and utilization of CO2. However, this reaction is limited by both the thermodynamic equilibrium and the kinetic barrier. In this study, we reported an innovative catalytic process to decompose CO2 in an oxygen-permeation membrane reactor packed with a mixed-conducting oxide supported noble metal catalyst, or Pd/SrCo0.4Fe0.5Zr0.1O3-delta (Pd/ SCFZ), which is of high activity in the decomposition of CO2 into CO and O2. Pd/SCFZ catalyst was prepared by incipient wetness impregnation of the SCFZ powders with an aqueous solution of PdCl2, and the CO2 sorption/desorption property was examined by in situ Fourier transform infrared spectroscopy and temperature-programmed desorption-mass spectrometry technologies. It was shown that there appeared a typical of bridged carbonyls (Pd-CO) on the surface of the Pd/SCFZ catalyst formed after CO2 decomposition. Both CO2 and CO could be detected in the species desorbed from Pd/SCFZ catalyst, which implied that the Pd/SCFZ catalyst could effectively activate the CO2 molecule. During the catalytic process, furthermore, the activity of the Pd/SCFZ catalyst can self-regenerate by removing the produced lattice oxygen through the dense oxygen-permeable ceramic membrane. At 900 degrees C, this catalytic process attains 100% of CO formation selectivity at 15.8% of CO2 conversions.
Nano-confined flow is ubiquitous in modern engineering and biomedical applications. As the peculiar phenomena of nano-confined flow were continuously reported and traditional theories failed to describe them accurately, simulation efforts have been made to gain deeper insight. The objective of this paper is to provide an overview of the recent progress on nano-confined flow, including water flow and hydrated ions transport. This report starts with the water behavior under nano-confinement, summarizing the water structures, flow properties and their dependence on wall wettability, channel size, etc. The report also presents the efforts made to modify the existing theories to describe nano-confined flows. Then, the report goes to the hydrated ions. The dehydration process of hydrated ions and ions sieving are discussed in detail, and the effects of membrane surface charge, grafting functional groups, and external field on ions transport are reviewed. In this Progress Report, the transport properties of water and hydrated ions in nano-confined channels are highlighted, which is critical to the design and application of nanofluidic devices, such as nanofiltration membranes, biosensors, and other related fields.
A visible-light responsive C, N and Ce co-doped TiO 2 mesoporous membrane has been synthesized via a weakly alkaline sol-gel route using P123 template. The co-doping of C, N and Ce resulted in a lowered band gap of 2.14 eV which improved the photocatalytic activity in visible light. The Ce-dopant was found to strengthen the Ti-O bond that stabilized the anatase phase as well as the assembled interconnected mesoporous structure during high temperature calcination. The stabilization of the crystal phase and pore structure resulted in a higher surface area, smaller and more uniform pore size in the membrane. The membrane exhibited a low cut-off molecular weight of 3300 Da and a water flux of 4.05 L m À2 h À1 per bar.
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