The effect of electrode materials on the co-generation of syngas and higher hydrocarbons from CO2 and CH4 using dielectric-barrier discharge has been investigated. The electrode materials tested here include aluminum, copper, steel, and titanium. For the feed of methane in the absence of CO2, the order of activity of methane conversion from high to low was Ti≈ Al > Fe > Cu, while the order of the activity of CO2 conversion was Al > Cu > Ti > Fe for the case of CO2 feed without methane. Regarding the co-feed of methane and CO2, the titanium electrode shows the best activity for the conversions, while the other three materials show a similar performance for the conversions. The effect of dilution gas, helium, on the conversions has also been discussed.

A diesel fuel additive has been synthesized from conversion of dimethyl ether(DME) using dielectric barrier dischargeŽDBD.plasma at atmospheric pressure and low temperatures. A high conversion of DME has been achieved. The product of such conversion is a mixture of hydrocarbons and oxygenates that can be used as high-performance diesel fuel additives. The maximum conversion of DME reached 47.2% with a selectivity of liquid product (a mixture of dimethoxy-containing hydrocarbons) more than 39.0% at 1208C and a 30 mlrmin flow rate of DME.

Previous investigations have found that the plasma catalytic conversion of methane is a low-emperature process for the activation of methane, the major component of natural gas. In this paper, the production of acetylene via plasma catalytic conversion of methane over NaY zeolite is discussed. Hydrogen is produced as a by-product during this plasma catalytic methane conversion. A methane/hydrogen feed with oxygen as an additive and helium as a diluent has been studied in this investigation. The CH4/H2/O2 system is found to be more selective for the production of C2 hydrocarbons, compared to the CH4/O2, CH4/H2O, and CH4/CO2 systems reported previously. A higher hydrogen concentration feed is more favorable for acetylene formation. The selectivity and yield of C2 hydrocarbons are related to the hydrogen feed rate, gas temperature, concentration of oxygen additive, and flowrate. The highest yield of C2 hydrocarbons (32%) is obtained at the lowest flowrate used (10 cm3/s; residence time

A novel catalyst preparation for NO reduction by CH4 has been conducted using a glow discharge plasma treatment followed by calcinations thermally. Such plasma prepared Pt/NaZSM-5 catalyst exhibits a high dispersion of metal active species. A remarkable improvement in the activity and stability, compared to the catalysts prepared conventionally, has been achieved. Especially, an excellent low temperature activity over the plasma-treated Pt/NaZSM-5 catalyst has been obtained. For example, the conventional 0.1 wt% Pt/NaZSM-5 catalyst shows no activity at temperatures below 673 K, while at 673 K, the NO conversion to nitrogen reaches 61.3% over the plasma-treated 0.1 wt% Pt/NaZSM-5 catalyst. The initiated temperature for the plasma-treated 0.1 wt% Pt/NaZSM-5 catalyst can be as low as 548 K.

A novel Pd/HZSM-5 catalyst was prepared first by glow discharge plasma treatment followed by calcination thermally. Such prepared catalyst shows a higher activity and an enhanced stability for methane combustion. The XRD characterization and XPS analysis confirm that the plasma preparation leads to a better preparation of PdO active species over the HZSM-5 support. Especially, a plasma-enhanced acidity has been achieved upon the FT-IR analysis. The enhanced acidity plays an important role in stabilizing the dispersed PdO active species on the zeolite support.