Yongkui Shan

Ordered Mesoporous Fe-Porphyrin-Like Architectures as Excellent Cathode Materials for the Oxygen Reduction Reaction in Both Alkaline and Acidic Media

Iron ORR: An ordered, mesoporous, Fe-porphyrin-like material was created through the nanocasting and pyrolysis of traditional Fe-N4 porphyrins. The resulting nonprecious metal electrocatalyst was used for the oxygen reduction reaction in both alkaline and acidic media.

Preparation and Catalytic Performance of Mesostructured Aluminosilicate Nano-particles with Wormhole-Like Framework Structure

A facile two-step sol–gel method has been developed for the preparation of mesostructured aluminosilicate nano-particles (Si/Al = 7.5) with wormhole-like but uniform pore structures and highly catalytic activities towards bulky hydrocarbon cracking. It is desirable that, as this synthesis takes place in the absence of alkali cations, the mesoporous nano-particulate material is directly obtained in the acid form, making a subsequent ion-exchange and calcination treatment superfluous.

Low-temperature activation of methane over rare earth metals promoted Zn/HZSM-5 zeolite catalysts in the presence of ethylene

Abstract At low temperature of 723 K, methane can be easily activated in the presence of ethylene in the feed, and converted to higher hydrocarbons (C 2 -C 4 ) and aromatics (C 6 -C 10 ), through its reaction over rare metals modified Zn/HZSM-5 zeolite catalysts without undesirable carbon oxides formation. Methane can get 37.3% conversion over the above catalysts under low temperature, and the catalysts show a longer lifetime than usual metal supported HZSM-5 zeolite catalysts without adding any rare earth metals. The effects of methane activation over various rare earth metal promoted Zn/HZSM-5 catalysts on the products and influences of several reaction conditions such as temperature, catalyst lifetime and molar ratio of CH 4 /C 2 H 4 have been discussed.

An innovative method for oxidative degradation of chitosan with molecular oxygen catalyzed by metal phthalocyanine in neutral ionic liquid.

A novel aqueous solution-ionic liquid biphasic catalytic system was established for the oxidative degradation of chitosan under mild conditions. In this process, the environmentally acceptable and inexpensive molecular oxygen was first used as oxidant, the metal phthalocyanine was immobilized in ionic liquid as catalyst, and the aqueous solution as medium carried the reactants and the products. Under vigorous stirring and heating, the reactants fully contacted the catalysts in the emulsion and chitosan efficiently degraded into water-soluble materials. At the end of the reaction, the catalytic system could be easily separated by simple decantation and could also be reused in subsequent runs without apparent change in activity. These characters are in favor of the elimination of pollution and the reduction of the economic cost in the large-scale production of the water-soluble chitosan derivatives in chemical industry.

Novel ionic liquids based on the benzimidazolium cation

A new series of salts, based on the benzimidazolium cation (Bim) and some common anions have been prepared. The salts were characterised by DSC, NMR, IR, elemental analysis and thermogravimetric analysis. They showed different properties such as melting point, thermal stability, multiple phase behaviour, and solubility properties compared to salts of the imidazolium cation.

High-rate oxygen electroreduction over metal-free graphene foams embedding P–N coupled moieties in acidic media

High-efficiency metal-free carbon electrocatalysts for the oxygen reduction reaction (ORR) in acidic medium are still a great challenge for the commercialization of the fuel cell technology. Herein, high-performance metal-free P,N-doped carbon catalysts (P–N-GFs-HMPA) with the E1/2 potential of about 0.78 V are successfully prepared by constructing porous foams using graphene oxides and carbon nanotubes as building bricks and hexamethylphosphoric triamide (HMPA) as the special precursor of P and N. Impressively, the HMPA compound not only facilitated the remarkable increase in the content of both P and N in the carbon frameworks, but also offered high density of the coupled N–P moieties embedded in the graphene surface. Together with the optimized local structures including open porosities and high electron transportation capacity, this foam exhibits excellent electrocatalytic performance for the ORR in acidic medium. It is markedly superior to the previously reported metal-free carbons and comparable to Fe- or Co-based ORR carbon electrocatalysts. Thus we have successfully developed a high-performance metal-free ORR catalyst in acidic medium by precisely tuning the carbon structure through coupling with non-metal elements.

Origin of the Ability of α‐Fe2O3 Mesopores to Activate C−H Bonds in Methane

Methane is a most abundant and inexpensive hydrocarbon feedstock for the production of chemicals and fuels. However, it is extremely difficult to directly convert methane to higher hydrocarbons because the C-H bonds in methane are the most stable C-H bonds of all hydrocarbons. The activation of the C-H bonds in methane by using an efficient and mild route remains a daunting challenge. Here, we show that the inner surface structures of the pore walls in mesoporous α-Fe2 O3 possess excellent catalytic performance for methane activation and convert C-H bonds into the C-O bonds in an O2 atmosphere at 140 °C. We found that such unusual structures are mainly comprised of turbostratic ribbons and K crystal faces and have higher catalytic activity than the (110) plane. These results are without precedent in the history of catalysis chemistry and will provide a new pathway for designing and preparing highly efficient catalytic materials.

Novel and Selective Method for the Aerobic Oxidation of Benzylic Alcohols in the Absence of Metal Catalyst

Abstract A metal-free aerobic oxidation of benzylic alcohols to the corresponding benzylaldehyde derivatives was accomplished using proton ionic liquids (pyridium nitrate) as catalyst in a nonsolvent system with excellent conversion and selectivity. The catalyst could be recycled with no other polluted emission in this reaction procedure.

Synthesis and structural characterisation of a new ferrous-ferric borophosphate: (NH4)0.5FeII0.5FeIII0.5(H2O)2BP2O8 0.5H2O

A new ferrous-ferric borophosphate was synthesised by hydrothermal conditions and structurally characterised by X-ray single crystal diffraction, IR, TGA, XPS as well as magnetic measurement.

A novel inorganic–organic hybrid material: hydrothermal synthesis and properties of [V6O12(CH3O)4(phen)4·4H2O] (phen = 1,10-phenanthroline)

An oxo-vanadium cluster [V6O12(CH3O)4(phen)4·4H2O] (phen = 1,10-phenanthroline) was synthesized hydrothermally and characterized by IR, XPS, TG-DTA and single crystal X-ray diffraction analysis. It crystallizes in the triclinic space group P , with cell parameters a = 9.709(1), b = 11.701(1), c = 13.365(2) Å, α = 74.430(2)°, β = 77.073(2)°, γ = 87.982(2)°, V = 1425.0(3) Å3, Z = 2. The crystal is built up as an organic–inorganic hybrid compound with an unusual oxo-vanadium skeleton and water molecules. Water molecules make up a tetramer linking neighboring oxo-vanadium clusters to form one-dimensional chains, and then further build up three-dimensional supramolecular arrays through the π–π stacking interactions of phen.