Wenling Chu

Selective oxidation of methane to syngas over NiO/barium hexaaluminate

The preparation, characterization and reactivity of NiO over barium hexaaluminate in the partial oxidation of methane is investigated. It is found that the prepared NiO supported catalysts are extremely active in the catalytic oxidation of methane, with 95% CH4 conversion and 98% CO selectivity achieved at 850°C. Highly disperse nickel oxide interacting with the support clearly shows the efficient use of the active nickel phase. In particular, the special structure of the barium hexaaluminate prevents its lattice from being destroyed by Ni ions when the Ni loading is as high as 20 wt%. The “layered aluminate type” structure of the barium hexaaluminate support can accommodate Ni ions in the structure so that there exists interaction between Ni ions and support, which causes the supported catalysts to possess excellent stability and capability to suppress carbon deposition.

Ce-Al Mixed Oxide with High Thermal Stability for Diesel Soot Combustion

Abstract A series of Al-doped CeO2 catalyst (n-AlCeO2, where n represents the molar ratio of Ce to Al in the samples) were prepared by a citric acid complexation-combustion method and used for soot combustion. There is a strong interaction between CeO2 and Al2O3 in the mixed oxide, and some aluminum can be incorporated into the CeO2 lattice forming a solid solution. The existence of J-Al2O3 in the mixed oxide obviously improved the thermal stability of CeO2 as a “diffusion barrier”, which induced a higher catalytic activity of the mixed oxides compared with the pure CeO2. For the Al-containing samples, the mobility of surface lattice oxygen seems to play an important role in soot combustion. The 30-AlCeO2 sample exhibited the highest soot combustion activity with the temperature corresponding to the CO2 + CO peak of 356 °C.

The Effect of Preparation Procedure on the Performance of Pd-SiW12/SiO2 Catalysts for the Direct Oxidation of Ethylene to Acetic Acid

Pd-SiW12/SiO2 catalysts were investigated to elucidate the effect of preparation procedure on the direct oxidation of ethylene to acetic acid. Pd-SiW12/SiO2 catalysts with a fixed amount of Pd and SiW12 were prepared in various ways. The order in which Pd and SiW12 were loaded on the SiO2 support and the treatment conditions for the supported Pd have a significant influence on the dispersion of Pd on the Pd-SiW12/SiO2 catalysts, but no influence on the concentration of B acid sites. The Pd-SiW12/SiO2 catalyst prepared by simultaneously loading Pd and SiW12 on the SiO2 support showed the best catalytic activity. The dispersion of Pd was the main factor in the catalytic activity.

Acrylic acid and electric power cogeneration in an SOFC reactor.

A highly efficient catalyst, MoV(0.3)Te(0.17)Nb(0.12)O, used for acrylic acid (AA) production from propane, was used as an anodic catalyst in an SOFC reactor, from which AA and electric power were cogenerated at 400-450 degrees C.

In Situ Electrochemical Synthesis of Oriented and Defect-Free AEL Molecular-Sieve Films Using Ionic Liquids

Simply preparing oriented and defect-free molecular-sieve films have been a long-standing challenge both in academia and industry. Most of the early works focus on the careful and multiple controls of the seeds layer or synthesis conditions. Herein, we report a one-step in situ electrochemical ionothermal method that combines a controllable electric field with ionic liquids. We demonstrate that an in-plane oriented and defect-free AEL (one molecular-sieve framework type) molecular-sieve film was obtained using an Al electrode as the Al source. The excellent corrosion-resistant performance of the film makes this technology promising in multiple applications, such as anti-corrosion coatings.

Influence of Noble Metals on the Direct Oxidation of Ethylene to Acetic Acid over NM/WO3-ZrO2 (NM = Ru, Rh, and Pd) Catalysts

Abstract Ru-, Rh-, and Pd/WO3-ZrO2 catalysts were studied for the direct oxidation of ethylene to acetic acid. The catalytic activity and selectivity depended strongly on the noble metals used. Rh/WO3-ZrO2 gave the highest conversion of ethylene, whereas Ru/WO3-ZrO2 was almost inactive. The higher catalytic activity was attributed to a better metal dispersion. Pd/WO3-ZrO2 gave the highest selectivity for acetic acid (75%), with the selectivity of the other two catalysts being rather low (∼10%). Temperature-programmed oxidation and H2 reduction experiments were used to show that the strength of the noble metal–oxygen bond played an important role in product distribution. A weak metal–oxygen bond favored the formation of acetic acid, while a strong metal–oxygen bond favored the combustion of ethylene to COx.

Highly Efficient Removal of CO in Effluent Streams from Real‐Life Propane Oxidation Process over CuO−CeO2−Based Catalysts

Selective removal of CO from the effluent streams in real‐life chemical processes is of great importance in many different fields of industry. Until now it remains challenging to use non‐precious metal oxides to selectively remove CO at low temperatures from real‐life chemical effluent with complex compositions. Herein, a series of binary and ternary transition metal oxide catalysts were prepared by co‐precipitation method and employed for the preferential removal of CO in the effluent stream (off‐gas) of propane selective oxidation. It was found that the CuO−CeO2−based mixed oxide catalyst exhibited the best CO removal performance, wider operating temperature window and higher resistance to the inhibition of hydrocarbons, H2O and CO2. The presented catalyst showed high potential for selective removal of CO in the off‐gas stream containing CO2, H2O and various hydrocarbons.

In Situ Monitoring of the Oxygen Activity on a Mg2V2O7 Catalyst during the Oxidative Dehydrogenation of Propane

Periodic oscillations in the oxygen activity on a Mg2V2O7 catalyst during the oxidative dehydrogenation of propane were monitored in situ by solid electrolyte potentiometry. The results directly showed that the catalyst was first reduced and then oxidized. The rate-determining step was the adsorption and activation of propane on the Mg2V2O7 catalyst. Propane and oxygen were adsorbed on different sites of the Mg2V2O7 catalyst.