This paper discusses catalyst preparation using thermal and cold plasmas. In general, there are three main trends in preparing catalysts using plasma technologies: (1) plasma chemical synthesis of ultrafine particle catalysts; (2) plasma assisted deposition of catalytically active compounds on various carriers, especially plasma spraying for the preparation of supported catalysts; (3) plasma enhanced preparation or plasma modification of catalysts. Compared to conventional catalyst preparation, there are several advantages of using plasmas, including: (1) a highly distributed active species; (2) reduced energy requirements; (3) enhanced catalyst activation, selectivity, and lifetime; (4) shortened preparation time. These advantages are leading to many potential applications of plasma prepared catalysts.

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.

A novel method for starch modification is investigated. Starch is highly cross linked by glow discharge plasma, without the assistance of conventional chemical agents, thus avoiding any environmental concerns. An energy-charge-transfer mechanism is suggested for the function of plasma. This process could be useful for the production of large quantities of modified starch.