We have previously reported an experimental investigation on synthesis of acetic acid directly from CH4 and CO2 via dielectric-barrier discharge. In this work, a DFT study was conducted using three hybrid DFT methods in order to understand the mechanism of such direct synthesis. It suggests that the synthesis is via two pathways with CO 2 and CO as key intermediates. The energy requirement with CO 2 pathway is much less than that with CO. The methyl radical formation and the dissociation of CO2 are two limiting steps for the synthesis of acetic acid directly from CH4 and CO2.

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.

Ni-Fe/La2O3 catalyst prepared by a glow discharge plasma treatment following calcinations thermally exhibits higher activity and selectivity compared to the Ni-Fe/La2O3 prepared conventionally. At the same reaction temperature, the CH4 conversion, CO selectivity and H2 selectivity obtained from the plasma prepared Ni-Fe/La2O3 are 5-9%, 4-7% and 9-15% higher than those from the conventional Ni-Fe/La2O3 catalyst, respectively. At the same methane conversion, the reaction temperature with the plasma prepared Ni-Fe/La2O3 is at least 100 C lower than that with the conventional Ni-Fe/La2O3.

Novel amorphous Ni-B catalysts supported on alumina have been developed for the production of hydrogen peroxide from carbon monoxide, water and oxygen. The experimental investigation confirmed that the promoter/Ni ratio and the preparation conditions have a significant effect on the activity and lifetime of the catalyst. Among all the catalysts tested, the Ni-La-B/γ- Al2O3 catalyst with a 1:15 atomic ratio of La/Ni, dried at 120℃, shows the best activity and lifetime for the production of hydrogen peroxide. The deactivation of the alumina-supported Ni-B amorphous catalyst was also studied. According to the characterizations of the fresh and used catalysts by SEM, XRD and XPS, no sintering of the active component and crystallization of the amorphous species were observed. However, it is water poisoning that leads to the deactivation of the catalyst. The catalyst characterization demonstrated that the active component had changed (i.e., amorphous NiO to amorphous Ni(OH)2) and then salt was formed in the reaction conditions. Water promoted the deactivation because the surface transformation of the active Ni species was accelerated by forming Ni(OH)2 in the presence of water. The formed Ni(OH)2 would partially change to Ni3(PO4)2.