In particular for exhaust-gas purification, different processes have been proposed. According to the invention, the polluted exhaust gas flows through a reactor volume to which non-thermal gas discharges are applied, while being brought into contact with a solid reducing agent at least once, and preferably several times. The reducing agent can, in particular, consist of carbon fibers. A suitable device for combining dielectric barrier discharges with the reduction has means for field enhancement substantially periodically spaced in the reactor.