Methods and devices are provided for the plasma-catalytic conversion of materials to produce chemical base materials. The methods and devices allow a plurality of chemical processes to be carried out in a plasma-catalytic manner to produce chemical base materials from simple raw materials (for example methane and biogas) with an improved selectivity and energy balance. A hydrocarbon-containing or other starting material is reacted under the action of a plasma to produce chemical base materials, or such a starting material is converted into an intermediate product in a first step under the action of a plasma, and the intermediate product is converted into the desired base material in a subsequent step. The devices for carrying out plasma-catalytic reactions are characterized by a jet pump arranged downstream of the plasma reactor, a tubular recipient (reaction chamber) having a diameter of at least 4 cm, or a catalyst-containing wall of the recipient.