Significant Synergistic Effect between Supported Ruthenium and Copper Oxides for Propylene Epoxidation by Oxygen

National Basic Research Program of China [2010CB732303]; NSF of China [21173172, 20873110, 21033006]; Key Scientific Projects of Fujian Province [2009HZ002-1]; Program for Changjiang Scholars and Innovative Research Team in University [IRT1036

Active site and reaction mechanism for the epoxidation of propylene by oxygen over CuOx/SiO2 catalysts with and without Cs + modification

Among alkali metal ions, Cs+ was found to be the most efficient promoter of the CuOx/SiO2 catalyst for the epoxidation of propylene to propylene oxide (PO) by O2. Stronger interactions between Cs+ and CuOx nanoparticles were proposed to favor the selective formation of PO. Kinetic studies indicated that PO was formed as a primary product in parallel with acrolein over the CuOx/SiO 2 catalyst, but PO readily underwent isomerization to allyl alcohol, followed by oxidation to acrolein, without Cs+ modification. The modification by Cs+ inhibited the isomerization of PO because of the weakened acidity, contributing to the increase in PO selectivity. The inhibition of the reactivity of the lattice oxygen in the presence of Cs+ also promoted PO selectivity by suppressing the allylic oxidation route. In situ X-ray diffraction, CO-adsorbed Fourier-transform infrared, and pulse-reaction studies suggest that CuI sites generated during the reaction account for the epoxidation of propylene by O2. ? 2012 Elsevier Inc. All rights reserved

Significant Synergistic Effect between Supported Ruthenium and Copper Oxides for Propylene Epoxidation by Oxygen

National Basic Research Program of China [2010CB732303]; NSF of China [21173172, 20873110, 21033006]; Key Scientific Projects of Fujian Province [2009HZ002-1]; Program for Changjiang Scholars and Innovative Research Team in University [IRT1036]Significant synergistic effects exist between RuOx and CuOx for the propylene epoxidation by oxygen. While supported CuOx and RuOx alone both catalyzed the formation of acrolein as the main partial oxidation product, the combination of RuOx and CuOx in an appropriate ratio afforded an efficient and stable epoxidation catalyst. The supported nanocomposites with the direct contact interface between CuOx and RuOx were proposed for propylene oxide formation (see figure)

Study on quasi two-stage compression cycle characteristics of the water heater of the air source heat pump in cold area

The water heater of an air source heat pump has the disadvantages of high exhaust temperature and weak heating performance in a cold area. The quasi two-stage compression cycle technology can effectively improve its operation characteristics in the cold area. In this paper, a rotor compressor with a medium pressure air supply is used to develop the water heater with R410A as the circulating working fluid. The system's heating performance under low temperature environments is experimentally studied. The results show that the exhaust temperature of the water heater system with the medium pressure air supply is lower than those without the air-supply system

Active site and reaction mechanism for the epoxidation of propylene by oxygen over CuOx/SiO2 catalysts with and without Cs+ modification

National Basic Program of China [2010CB732303]; Natural Science Foundation of China [21173174, 21033006, 21161130522, 20923004]; Program for Changjiang Scholars and Innovative Research Team in University [IRT1036]; Key Scientific Project of Fujian Province [2009HZ0002-1]Among alkali metal ions, Cs+ was found to be the most efficient promoter of the CuOx/SiO2 catalyst for the epoxidation of propylene to propylene oxide (PO) by O-2. Stronger interactions between Cs+ and CuOx nanoparticles were proposed to favor the selective formation of PO. Kinetic studies indicated that PO was formed as a primary product in parallel with acrolein over the CuOx/SiO2 catalyst, but PO readily underwent isomerization to ally] alcohol, followed by oxidation to acrolein, without Cs+ modification. The modification by Cs+ inhibited the isomerization of PO because of the weakened acidity, contributing to the increase in PO selectivity. The inhibition of the reactivity of the lattice oxygen in the presence of Cs+ also promoted PO selectivity by suppressing the allylic oxidation route. In situ X-ray diffraction, CO-adsorbed Fourier-transform infrared, and pulse-reaction studies suggest that Cu-I sites generated during the reaction account for the epoxidation of propylene by O-2. (c) 2012 Elsevier Inc. All rights reserved

Photocatalytic Conversion of Carbon Dioxide with Water into Methane: Platinum and Copper(I) Oxide Co-catalysts with a Core-Shell Structure

National Basic Research Program of China [2010CB732303, 2013CB933100]; NSF of China [21033006]; Program for Changjiang Scholars and Innovative Research Team in University [IRT1036

Mesoporous Zeolite-Supported Ruthenium Nanoparticles as Highly Selective Fischer-Tropsch Catalysts for the Production of C-5-C-11 Isoparaffins

NSF of China [20625310, 20923004, 21033006]; National Basic Program of China [2010CB732303]; Key Scientific Project of Fujian Province [2009HZ0002-1]; Doctoral Program of Higher Education [20090121110007

Mesoporous Zeolite-Supported Ruthenium Nanoparticles as Highly Selective Fischer-Tropsch Catalysts for the Production of C(5)-C(11) Isoparaffins

NSF of China[20625310, 20923004, 21033006]; National Basic Program of China[2010CB732303]; Key Scientific Project of Fujian Province[2009HZ0002-1]; Doctoral Program of Higher Education[20090121110007