Formation of Methane and Ethylene in Methanol Conversion over HZSM-5 Catalyst

Primary formation of methane and secondary formation of ethylene in methanol conversion are evidenced by temperature-programmed-surface- reaction of adsorbed methanol on HZSM-5 catalyst.A reaction mechanism accounts for the observed results is described.

THE XPS STUDY OF Cu-Co BASED CATALYSTS FOR SYNGAS CONVERSION TO ALCOHOLS

The copper-cobalt based catalysts were effective for higher alcohol synthesis, the surface state of the catalysts and the nature of the active sites were investigated by using XPS and XAES spectra, and some strong interactions were also observed, in each of the three cases, (after calcination, after reduction, and during the syngas reaction).

NOx storage and reduction assisted by non-thermal plasma over Co/Pt/Ba/γ-Al2O3 catalyst using CH_(4) as reductant

NOx storage and reduction(NSR)technology has been regarded as one of the most promising strategies for the removal of nitric oxides(NOx)from lean-burn engines,and the potential of the plasma catalysis method for NOx reduction has been confirmed in the past few decades.This work reports the NSR of nitric oxide(NO)by combining non-thermal plasma(NTP)and Co/Pt/Ba/γ-Al2O3(Co/PBA)catalyst using methane as a reductant.The experimental results reveal that the NOx conversion of NSR assisted by NTP is notably enhanced compared to the catalytic efficiency obtained from NSR in the range of 150°C–350°C,and NOx conversion of the 8%Co/PBA catalyst reaches 96.8%at 350°C.Oxygen(O_(2))has a significant effect on the removal of NOx,and the NOx conversion increases firstly and then decreases when the O_(2)concentration ranges from 2%to 10%.Water vapor reduces the NOx storage capacity of Co/PBA catalysts on account of the competition for adsorption sites on the surface of Co/PBA catalysts.There is a negative correlation between sulfur dioxide(SO_(2))and NOx conversion in the NTP system,and the 8%Co/PBA catalyst exhibits higher NOx conversion compared to other catalysts,which shows that Co has a certain SO_(2)resistance.

A 3D MIL-101@rGO composite as catalyst for efficient conversion of straw cellulose into valuable organic acid

Efficient conversion of straw cellulose to chemicals or fuels is an attracting topic today for the utiliza-tion of biomass to substitute for fossil resources.The development of catalysts is of vital importance.In this work,a composite catalyst metal-organic frameworks(MOFs)immobilized on three-dimensional reduced graphene oxide(3D-rGO)were synthesized by in situ growth of the MIL-101(Cr)within the 3D-rGO matrix.The supporting of 3D-rGO guaranteed the dispersion and acid site density of MIL-101(Cr).The MIL-101(Cr)@3D-rGO nanocomposite possesses excellent catalytic activity,stability,recyclability and is an idea catalyst for the efficient degradation of straw cellulose into formic acid(FA),acetic acid(AA)and oxalic acid(OA).A maximum FA conversion rates of 95.36%was obtained by using MIL-101(Cr)@3D-rGO(1:1)as catalyst and hydrothermal reaction at mild conditions of 200°C for 1h in alkaline aqueous medium.The MIL-101(Cr)@3D-rGO nanocomposite can be reused with high catalytic activity without any collapse of structure or leaching of chromium.

Hydrochlorination of acetylene using expanded multilayered vermiculite(EML-VMT)-supported catalysts

Catalyst supports have very important effects on catalyst performance.A novel expanded multilayered vermiculite（EML-VMT） is successfully used as the catalyst support for the acetylene hydrochlorination.By mixing carbon on the surface of EML-VMT[i.e.,EML-VMT-C）,the HgCl2/EML-VMT-C achieved a high acetylene conversion of 97.3%,a vinyl chloride selectivity of 100%and a turn over frequency（TOF） value of 8.83 × 10^-3s^-1 at a temperature of 140 C,an acetylene gas hourly space velocity（GHSV） of 108 h^-1,and a feed volume ratio V（HC1）/V（C2H2） of 1.15.Moreover,the HgCl2/EML-VMT-C shows good stability.The EML-VMT also shows potential in the preparation of other EML-VMT-supported catalysts.

Catalytic performance of a Pt-Rh/CeO_2-ZrO_2-La_2O_3-Nd_2O_3 three-way compress nature gas catalyst prepared by a modified double-solvent method

A Pt-Rh three-way catalyst（M-DS） supported on CeO_2-ZrO_2-La_2O_3-Nd_2O_3 and its analogous supported catalyst（DS） were developed via a modified double-solvent method and conventional double-solvent method, respectively. The as-prepared catalysts were characterized by N_2 adsorption-desorption, X-ray diffraction（XRD）, CO-chemisorption, X-ray photoelectron spectroscopy（XPS） and hydrogen temperature-programmed reduction（H_2-TPR）. The preformed Pt nanoparticles generated using ethanol as a reducing agent on M-DS presented enhanced Pt dispersion regardless of aging treatment as confirmed by XRD and CO-chemisorption measurements. The textural properties and reduction ability of M-DS were maintained to a large extent after aging treatment. This result was consistent with those of the N_2 adsorption-desorption and H_2-TPR, respectively. Meanwhile, the XPS analysis demonstrated that higher Pt^0 species and larger Ce^（3＋） concentration could be obtained for M-DS. In the conversion of a simulated compressed natural gas（CNG） vehicle exhaust, both fresh and aged M-DS showed a significant enhancement in the activity and N_2-selectivity. Particularly, the complete conversion temperature（T_（90）） of CH_4 over the aged M-DS catalyst was 65 oC lower than that over the aged catalyst by conventional double-solvent method.

Successive Free-Radical C(sp^(2))-C(sp^(2)) Coupling Reactions to Form Graphene

Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately few-layer graphene,due toπ–πstacking,and single-layer graphene from reaction between hexabromobenzene and Na metal,followed by annealing to improve crystallinity.The reaction proceeds via a free-radical C(sp^(2))–C(sp^(2))coupling mechanism,which is supported by theoretical calculations.The graphene can host unpaired spin electrons,leading to a short acquisition time for a solidstate nuclear magnetic resonance 13C spectrum from unlabeled graphene,which is ascribed to the very short spin-lattice relaxation time.High catalytic activity for transforming amine to imine with a conversion of>99%and a yield of∼97%is demonstrated,and high electronic conductivity of∼105 S·m^(−1) is found by terahertz spectroscopy.The reaction delivers a method for synthesizing graphene with a high spin concentration from perbrominated benzene molecules by using an active metallic agent,such as Na,Li,or Mg.